Hole bridge

Torpedo or cable head caught in a key seat Cable or tool differentially stuck Tool caught in a split casing shoe. The normal procedure to attempt to free a stuck tool is to pull tension on the wire up to just below the breaking strain of the weak point, or as advised by the Logging Engineer. Sometimes, pulling on the cable does not free the tool and on the contrary it may trap the tool further. When the wireline is still intact it is best to use a cable guide technique where the wireline will...

Casing hanging before the second stage cementing

The points discussed above show there is an opportunity to hang the casing before the second stage cement job, adopting the use of a special designed base flange or a modified casing spool with four 4V16 outlets instead of the normal two 13 4 ones). In this case, well control, which is impossible during lifting of the BOP stack, is implemented, since the annular hydraulic conditions are restored after the mud circulation through the Stage Collar. Therefore, the BOP stack is lifted and the...

Junk Basket Drilling Procedure

1) This procedure is more successful in soft formations. 2) A reverse circulation type junk basket is preferred to a forward circulation type. 3) Use the following parameters Low Pump Rate ( 2 pump rate while drilling). 4) Core approximately 20cm. Pick up to allow the junk on the side of the basket to fall into the pilot hole, then proceed coring a further + -50cm. 5) Pull the junk basket out of the hole 6) After use, careful inspection and refurbishment is necessary.

Running The Bop And Riser System Bop Stack And Riser Preparation

After 20 casing has been run and cemented, the BOP stack and the riser will be run and The BOP stack must be checked and tested and the riser elements inspected in order to have the equipment ready to run as soon as possible after cementing the 20 casing. The following is a list of suggested inspections and tests. 2) Check the sealing elements for wear or damage. 3) Clean the bore and the ram cavities with a high pressure stream of water in order to be able to detect the presence of dents. 5)...

Remedial Action While Drilling

As soon as any irregularity is observed in the mud returns, the following procedure should be conducted 1) Check the surface equipment for leaks. 2) Run a subsea TV or ROV down the length of the marine riser, flex joint and BOP stack on both sides. When there is doubt or visibility is poor, close the BOP rams and check if the level still drops when the hole is isolated from the riser system. 3) If still losing mud, stop pumping and observe the well. 4) If the level remains static, the mud...

Use Of Dob And Dobc Pills

1) If the tripping is considered safe (i.e. the hole stands full of mud), run open ended drill pipe to 10 to 30m above the thief zone. 2) Pump the pill and displace it with mud to the bottom of the string. 3) Close the BOP and squeeze pump down the annulus and the pipe at the same time. The flow rate shall be the same in both the annulus and in the drill pipe if DOB pills are being used. In case of DOBC pills, the flow rate in the annulus shall be half the flow rate in the drill pipe being used...

Reduced Bit Weight

Drill Collar Bend

By reducing the weight on the bit, the bending tendency of the drill string are changed and the hole will be straighter. One of the earliest techniques for straightening the hole was to reduce the weight on the bit and speed up the rotary table. In recent years it has been found that this is not always the best procedure because reducing the bit weight sacrifices considerable penetration rate. Worse than this, it frequently causes dog-legs as illustrated in 8.7. Therefore as a point of caution,...

Running Of Liner

1) Check the inside diameter and rated load of the drill pipe. 2) Run the 7 liner checking the weight and circulate the liner capacity after the making up of hanger to check the setting tool seal. 3) Set the liner as per the Manufacturer's Procedure or as per section 12.7. 4) Cement as per the 'Casing Running and Cementing' section 12, pull the stinger out of the liner, circulate out the excess cement and condition the mud. 5) Pull ten stands, circulate and wait on cement. Circulate, pull the...

STAPPM

1) After open hole log, a trip to bottom is recommended to condition the hole and mud. The Mud Engineer shall check and, if necessary, adjust the mud properties. Plastic viscosity, yield strength and weight shall be kept as low as possible. 2) There is a difference between the driller's and logging depths, strapping in or out of the drill string shall be considered. 3) Check the weather forecast to ensure conditions be such as to allow safe operations. 4) Replace the upper pipe rams with the...

Tangent Section Hold On Section

When the desired inclination has been reached, the kick off or build up assembly is replaced with a stiff bottom hole assembly that will maintain the inclination and direction. Small variation in behaviour of a BHA can be obtained by adjusting the weight on bit and rotary speed. figure 9.k, illustrates some common holding assemblies. Providing it is necessary, the earlier a correction to inclination or direction can be made the better it is. As the bit get closer to the target, longer...

Primary And Secondary Packing Group Test

To properly test the primary and secondary packing groups it is necessary to have the following components and fittings High pressure hydraulic test pump assembly complete with hose. 1 2 needle valve, 1 2 NPT Pin. Tee, V2 NPT XX Heavy Box x Box. Bushing, 3 4 x 1 2 NPT Pin x Box Reducing bushing attached to the pump hose end, 2 NPT Pin x Pin. Nipple, 1 2 NPT XX Heavy x 10 long Pressure relief needle valve. After completion of the casing spool and packing assembly, proceed to testing the packing...

Operating Limits Of Drill Pipe

The design of the drill string for static tensile loads requires sufficient strength in drill pipe to support the submerged weight of drill pipe and drill collar below. The submerged load (P) hanging below any section of drill pipe can be calculated as follow Weight per foot of drill pipe in air Weight per foot of drill collar in air The difference between the maximum allowable tension and the calculated load represents the Margin of Over Pull (MOP) Pt Theoretical tension load from table 0.9...

Preventive Measures

Problems are usually suspected by increase in drag during connections. Once the cause is recognised to be any of the three previously listed, the following actions should be undertaken 1) Reduce mud filtrate, cake and solids content. 4) Increase mud clearing capacity. In all situations, frequent wiper trips can reduce the problem and provide information on the severity.

Drilling Slim Hole Or

1) Run a 57 8 or 6 bit and drill out the cementing equipment in the 7 liner or casing. 2) Drill 5m of new hole, condition the mud and perform a leak of test, if required. 3) Drill the 57 8 or 6 hole to the planned depth following the specified Mud and Hydraulic Programme. 4) At TD make a wiper trip up to the 7 casing shoe, run to bottom again and circulate to condition the mud. Pull out of the hole. 5) Run logs as per the Geological Programme.

Drilling And Cementing CP

1) Run a 26 bit + float valve + 36 Hole Opener + 1 x 9 Monel DC + 1 x 9 Spiral DC + 5 HWDP + 5 DPs in offshore operations whith Jack-Ups down to the seabed and measure the water depth. 2) Drill to the depth of the first two joints using high viscosity mud (80-120 seconds Funnel viscosity) and at a very slow pump rate, in offshore operation whith Jack-Ups space out in order to avoid pulling the bit above the mud line at the first connection and. 3) Drill the remaining 36 hole down to the a...

Float Equipment Not Holding Cementing

17) Displace the cement with mud at the maximum permissible rate and surface pressure, unless otherwise stated in the Cementing Programme. 18) Slow the pumps, if there is a loss of returns during the displacement, to regain circulation. 19) If returns cannot be regained, continue to displace the cement at the lowest permissible rate (unless otherwise advised) record the returns. 20) Stop displacement only in the event the pressure exceeds 70 of the casing burst pressure or 5,000psi, whichever...

A Hydraulic Control Systems

The main components of a hydraulic control system are shown in figure 5.e. A master hydraulic power unit supplies fluid to both pilot and hydraulic lines via accumulator bottles. The stack can be controlled from this unit or from a remote control panel on the rig floor or an electric mini panel usually located in the rig office. Pilot and operating fluid is provided to stack via one of two hose bundles each of which terminates in a Pressure Operating Device (conventionally termed yellow or blue...

Handling and running CRA tubulars

1) Do not use lift hooks to pick-up CRA pipe. The joints should be lifted to the 'V' door by nylon slings. 2) The elevator must be placed on the pipe only after the joint is made-up. 3) A safety clamp will be securely placed around the joint located in the slips to prevent slippage (X-line or flush coupling). 4) Keep thread protectors on the Pin and Box until stabbing to avoid loose scale or debris interfering with the make-up. 5) The use of an integral back-up power tong is recommended with a...

Squeezing

1) Set a Cement Retainer (CR) using wireline whenever possible to 5 to 10m above the perforations. Correlate the CCL and GR to avoid setting the CR across a collar or perforations. 2) Run the Setting Tool on drill pipe, apply 10 ton weight on the CR and try to circulate testing the CR and the rubber seals ('0' rings) by pressurising up on the annulus. Pickup the stinger and test the surface lines from cementing unit to cementing head at 5,000psi. 3) Displace the pipe with 2m of water cushion....

Loss Preventive Measures

The depths where losses can be expected for each particular well, are usually predicted in the Drilling Programme, if enough information is available. If thief zones are likely to be encountered, the following procedure should be adopted 1) Keep the mud weight as low as possible but still providing an adequate overbalance. 2) Control the ROP to prevent overloading the annulus with cuttings which could result in increased mud densities and or constrict the annulus. 3) Maintain a low yield point...

Build Up Section

After the desired direction has been reached, the kick off assembly may be replaced with a rotary build up assembly. However, if jetting has been the method of initial control, drilling can continue with the same BHA in the rotary mode without requiring a trip. Selection of the appropriate build up assembly is dependent upon the angle achieved during initial kick off and maximum angle required. figure 9.i illustrates the response of some bottom hole assemblies. The decision of when and if to...

Stuck Pipe

The following is a list of the different types of pipe sticking which can occur due to Hole irregularities and or change in BHA. It is impossible to lay down hard rules which will successfully cover all cases. however, for each situation, indications about the possible causes of the problem, preventive measures and remedial actions are listed in the following subsections. Detailed procedure should be based on each particular case, evaluating every aspect of the problem and applying any past...

Bottom Hole Assembly Buckling

Without weight on the bit, a drill string is straight if the hole is straight. With a sufficient small weight applied on the bit, the string will remain straight. As the weight is increased, a critical value of weight is reached and the drill string will buckle and contact the wall of the hole. If the weight on the bit is further increased, a new critical value is reached at which the drill string buckles a second time. This is designated as 'buckling of the second order'. With still higher...

Handling Radioactive Sources

The radioactive sources are in the form of pellets which are permanently encased in a metal shield (packing) even during logging. This shield decreases the energy and hence the range When the source is not in use, it shall be kept in a second metal shield, which further reduces the energy and range of the emissions. 1) Offshore transportation is generally conducted by ship. When transported by ship, the source shall be secured in a shipping container so as to avoid damage to the packaging. The...

Milling Procedure

There is a wide variety of mills specifically designed for various applications. Mills are available in two basic categories 'hydraulically activated mills' and 'fixed milling tools'. A Section Mill is a hydraulically actuated tool and is used to mill out a complete section of casing. Downhole section milling of casing, is generally done for the following reasons To mill a section of casing that permits side-tracking in any direction. To mill the perforated zone in a production casing string or...

Drop Off Section

Drilling a directional well it may be necessary to allow the drift angle to straighten back to vertical or near vertical. figure 9.l shows some common drop off assemblies. Drop off assemblies should be used starting with the least successful. The reason being that the higher the inclination, the greater the pendulum effect and the same rate of drop might be achieved with the least successful assembly at 50o and the most successful assembly at 30o. Therefore, as the inclination is reduced,...

Onshore Planning

Due to the peculiarity and complexity of MWD LWD operations, a very high degree of collaboration is required between the Drilling & Completion Department specialist, Subsurface Geologist Department specialist and Service Company Representative, in the pre-job meeting for the operation to determine The most suitable tools. Their positioning in the BHA The drilling parameters to be used If the stabilisers are correctly positioned in the BHA, according to the LWD tools The maximum admissible...

Lost Circulation

When lost circulation is encountered, some specific information regarding the situation is required prior to initiating corrective procedures. First, it is necessary to determine the magnitude of the losses. These may vary from minor seepage losses to partial and complete loss of returns. Second, the condition at the time of losses may proved an indication of the reasons for the lost of circulation. Losses during tripping are usually due to running pipe too quickly. During drilling, a change in...

Straight Hole Drilling

It has been confirmed through observation that a drilling bit will attempt to up move toward an up dip in laminar formations with dips angles up to 40o. A factor in consideration of this is the bending characteristics of the drill string. With no weight on the bit, the only force acting on the bit is the result of the gravitational weight of the portion of the string between the bit and the tangency point. The force caused by this weight tends to bring the hole back towards vertical. When...

Example

UTM co-ordinates of the rig 410,261.0 E 6,833,184.2 N The rig is 500,000 - 410,261m west of the central meridian and 6,833,184.2m north of the equator. The bearing between any two points in the same grid sector is referenced to Grid North which is the direction of a straight line running from top to bottom of the map. Convergence is the angle 'a' Refer to figure 9.b between the Geographic North and the Grid North for the location being considered measured from Geographic North. In the northern...

Riser And Diverter System

The riser system provides communication between the wellhead and the rig floor in order for tools to be guided into the well and provide a return path for mud to surface. A riser systems consists of a number of elements d Lower Flex Joint or Ball Joint The most important single parameter in the design and operation of a marine riser is the tension applied at the top of the riser. This tension is provided by a system of pneumatic-hydraulic pistons attached to wire ropes which are in turn...

BOP Control System

The simplest form of BOP control is to assign a hydraulic line direct to each individual function. This presents little problem on land rigs where the large number of control lines required can be easily handled and the distance the control fluid has to travel is not great. On a subsea stack, this direct control is impractical, too many individual lines would be needed and the pressure drop inside them would be too great for the reaction time to be acceptable. For this reason, other systems...

Cementing Surface Casing With Inner Strings

1 Run all the 20 casing in the hole and stab on the landing ring. 2 Run the inner string into the casing down to the shoe. 3 Run the two 2 8 tubing strings into the 20-30 annulus. Tag the landing ring and wash out with sea water. At the same time, make up the cementing line and fill-up the 20 casing 5 DPs annulus with sea water. Break circulation and check if the stinger 'O' rings are sealed. 4 Pressure test the cementing line and cement the 20 casing as per the Cementing Programme. 5 When...

Drilling Directional Wells Kicking Off The Well

Jetting is the term used to describe the deviation of a well using bit hydraulics to erode the formation in a particular direction. A special jetting bit may be used or a conventional tricone bit run with two undersized and one oversized or blanked jet nozzles. Usually the bit is run on a typical build up assembly bit, full gauge near bit stabiliser, orienting sub, non-magnetic and steel-drill collars as required and once on bottom the blind nozzle, representing the 'tool face', is oriented in...

Klepto Inflatable Thread Protector

Selection shall be based on desired make-up torque and casing size. To avoid bending and shearing forces on casing. To automatic drop the speed of the tong before reaching the shoulder. Single joint elevator Lifting sub Nylon lifting sling Elevator Rotary handslip Spider elevator Stabbing guide Manual chain tong Safety clamp Selection shall be based on casing size and weights Air inflatable thread protectors or similar. Selection on casing sizes and thread types. It provides positioning control...

Info

1 Yield and ultimate capacities are calculated based on minimum material properties, under single load conditions, and are based on test and or analysis. 2 All ratings include weld preps. Other wall size and special application connectors are available. NOTE . RL-1S and RL-4S connectors are not interchangeable. Table 4.D - Squnch Joint Connectors continued

General Guidelines

1 All depth measurements will be referenced to RKB rotary kelly bushing . 2 A stock of diesel oil, enough for five days of operations, must always be kept on the rig 3 A stock of barite usually 100t is accepted as the minimum stock level calculated on the basis of the estimated overpressure development, refer to section 6.5 must be kept on the rig all time during drilling operations. 4 BHA equipment and drill pipe must be inspected by non-destructive tests, as specified in the drilling rig...

Index

UPDATING, AMENDMENT, CONTROL amp DEROGATION 8 3.1.1. Well Site Reports 10 3.1.2. Other Well Site Reports 11 3.2. Contractor Performance 11 3.3. Report Distribution 12 4. SUMMARY OF OPERATIONS Land Rig or Jack-Ups 13 4.1. Conductor Pipe Installation 13 4.1.2. Final Refusal Depth 18 4.1.3. Conductor Pipe Connections 19 4.1.4. 30 CP Driving Procedure 23 4.1.5. Drilling And Cementing CP 30 4.2. Drilling 26 Hole 31 4.2.3. Single Well Using Pilot Hole Technique 33...

Explain Single Shot Survey Calculations

1 Inspect the DP after a certain amount of thousand feet is drilled, or rotating hours, specified by the Company Drilling Office. This operation shall be carried out by a recognised inspection company. Drill collars, stabilisers, subs, etc. shall be checked at the end of each well. 2 Read the single shot survey film discs or MWD data to ensure the correct path is being followed. 3 Check survey calculations for correctness. 4 Keep well plot updated every time a new survey is taken. 5 The baffle...

Running Procedure

1 A circulation sub, fitting the casing thread, equipped with a WECO connection, shall be readily available on rig floor at all times during casing running. 2 Pick up the shoe joint and remove the blank thread protector at V-door. Lower the joint through the rotary and visually verify for back flow. Fill the joint with mud, then pick up to check for flow through. 3 Generally a float collar shall be run two joints above the shoe in 133 8 and 95 8 casing and three joints above a 7 shoe. 30...

Final Refusal Depth

The following procedure details the determination of final refusal depth. 1 When the driving depth of the conductor pipe is not specified in the Drilling Programme, the final depth of the driving is the 'refusal depth'. The refusal value generally used is 1,000-1,100 blows metre. Local experience could dictate a different refusal value. The driving depth can be predetermined by conducting soil boring analysis. Examine offset well data for depths and potential problems in order to determine if...

A Diverter System

The subsea diverter system is an integral part of the marine riser system. Diverter mechanism consists primarily of a packing insert that can seal on drill pipe or open hole with an insert plug , a control system, two flow lines, a ball joint and valving. The Regan Hughes Offshore KFD diverter is the most common system used on today's rigs. There are three basic models KFDG Gimble which is used on rigs that do not have an upper ball joint. KFDH Housing used on many vessels having limited room...

Casing Operations With A Top Drive

With the introduction of 500 tons bails and adequately rated swivel, the Top Drive is rated at 500 tons for casing operations. Longer bails 132 or 144 must be used to allow clearance for the casing elevator under the torque wrench in the pipe handler. Also clearance for the cementing head must be taken into consideration when determining casing bails length. By attaching a short piece of hose to the saver sub in the pipe handler, the casing can be filled while lowering by using the remotely...

Recommended Flange Bolt Torque

API Specification 6A seventeenth edition 1996 It should be recognised that applied torque to a nut is only one of several ways to approximate the tension and stress in a fastener. The following table 15.c is for the convenience of the user only, and is based on calculations which assume certain friction coefficients for the friction between the studs and nuts, and between the nuts and the flange face. Two coefficients of friction are used in the table 0.13 approximates the friction with...

Testing The BOP Stack

1 Retrieve the 18 4 nominal seat protector. Do not land the test plug on the seat protector since test pressure will force the protector down, swedging it into the housing. 3 Fill the running string to the top with water. The string must remain open to atmosphere during the entire test. 4 Pressure test the BOP stack as per Eni-Agip Division and Affiliates Well Control Policy using either one of the two pods. A BOP function test must then be performed on the other pod.

Mudline Suspension System Running Procedure

Mudline Hanger Pics

Mud Line Casing Suspenion System With Running Tools Mud Line Casing Suspension System With Tieback Tools Figure 15.L - MLL Mudline Casing Suspension System Mud Line Casing Suspenion System With Running Tools Mud Line Casing Suspension System With Tieback Tools Alternative 9 5 8 Mud Line Hanger with 9 5 8 Hanger Sub Accomodates 7 Hanger Figure 15.L - MLL Mudline Casing Suspension System

Note In relation to the drift angle of a directional well mud density and mud rheological properties

Follow the manufacturer's procedure for the stage tool opening pressure and approximate bomb landing time. If difficulty is experienced in opening the stage collar occurs, re-check the pumping circuit and relevant valves before a final decision is made to reduce the tension on DV sleeves by slacking-off weight of the hook. 4 With the stage collar opened, start circulation with a low pump rate, keeping the mud level under control. Increase the pump rate only when it is...

Stappm And Drilling

The following formula is often used to calculate the pill's volume. 'Drop' is in ft and represents the desired draw down in the string. 'Mud Weight' is in PPG. 'DP Capacity' is in BBL ft. 7 The 'Wiper rubber' should be used when pulling or running the drill pipe to prevent any objects falling into the hole. Do not install the wiper rubber while tripping out the first 10 stands in order to observe the fluid level. 8 In an area where formations contain or are suspected to contain hydrogen...

Minimum Stock Requirements

A Minimum stock requirements for mud weighting materials, chemicals, pipe freeing agent, dispersant, lost circulation material, cement, kill and reserve mud on the rig, depends on the well pressure prognosis, severity of potential drilling problems and rig load capacity. b The minimum barite stock shall be 100t. When overpressurised formations are anticipated, barite stock shall be based on expected formation pressure gradients, on the actual mud weight and on the volume of the active drilling...

Cementing And Displacement Procedure Single Or First Stage

Break circulation slowly. When it has been determined that full returns have been established, gradually increase the pump rate and circulate total hole volume. Record the pressures at the various flowrates. At the end of circulation, record the pressure with estimated displacement rate. 2 During circulation monitor pit levels, bottoms-up mud properties and eventual shows. 3 After bottom circulation, line up the cement head to the cementing manifold. 4 Check the...

Base Flange Installation Welding Procedure

1 Cut the 30 CP at cellar deck level Jack-up or at cellar bottom land rig . 2 Cut the 20 casing at about 50cm above the cellar deck or cellar bottom 3 Empty the casing of mud bringing the fluid level down to 50 cm below the cellar deck or cellar bottom. 4 Pre-heat the casing in the proximity of the final cut line up to the same temperature required for welding. 5 Cut the casing at about 200-400mm from cellar deck or cellar bottom according to the Drilling Programme, with a 30-35 internal bevel,...

Responsibilities

1 The Company Drilling and Completion Supervisor is the person in charge of all casing running and cementing operations. 2 The Company Drilling Engineer should be present on the rig, whenever possible, for the intermediate casing operations and to assist the Drilling And Completion Supervisor during critical phases, providing technical assistance. 3 The Company Drilling and Completion Supervisor shall ensure that all pipe is correctly measured, all equipment is of proper size and type specified...

Tubing Spool Installation

1 Clean the ring grooves on the bottom flange of tubing spool and on the casing spool, as well as the restricted packing bore of the tubing spool. 2 Oil the secondary packing and the restricted packing bore of the tubing spool. 3 Fill the void area with oil around the primary and secondary packing group. 4 Install the metal ring gasket in the ring groove on the casing spool. 5 Install the bolts in the bottom flange of the tubing spool. 6 Align the bolt holes on the tubing spool with the bolt...

Well Site Reports

It is vitally important that the operation process is fully recorded and documented in a consistent format, therefore, standard feed-back or report forms with relevant filling instructions for ensuring a consistent and homogeneous method will be used in technical data reporting of world wide activities. It will be the responsibility of the ENI-AGIP and Affiliates Drilling And Completion Supervisor to ensure the correct filling in and forwarding of the appropriate forms reports to the Company...

Bop Stack Equipment

Floating drilling rigs may be equipped with either a 'one stack' or a 'two stack' BOP system. The two stack system is a combination of a 2,000 or 3,000psi large bore stack and a 5,000, 10,000 or 15,000psi stack. A one stack system is either a 10,000 or 15,000psi system. The following list gives the common sizes and various configurations 183 4 - 10,000 and 15,000psi WP 163 4 - 10,000 and 15,000psi WP 135 s - 5,000, 10,000 and 15,000psi WP 4 rams and 2 annulars 4 rams and 1 annular 3 rams and 1...

Drilling Hole

Drill out the 17 2 float collar, cement, casing shoe and wash down to the rat hole TD. If it is planned to drill a long section, install a wellhead bore hole protector into the first casing spool. 2 Drill 5m 15ft of new hole, condition the mud and perform a leak off test Refer to section 11 . 3 Resume drilling with the 12 4 bit using the proper BHA for a vertical or deviated hole. 4 Drill the 12 4 hole down to KOP and, if in a deviated hole phase, change the BHA for...

Casing Check List

Within a reasonable time prior to the beginning of the casing operation, the Company Drilling and Completion Supervisor and the Drilling Contractor's Toolpusher shall physically check the availability on the rig of all materials necessary to operations. The following check list may be used as a guideline. a Casing joints, enough for planned depth with 5-10 excess or a min. of 10 joints. b Float equipment float shoe, float collar, stage collar back-up are recommended . e Solvent to clean casing...

Note The diverter system is not a blowout preventer and is not designed to hold pressure but only to

4 Drill the 26 hole down to the planned depth as per the Drilling Programme. 5 Begin drilling with an unweighted gelled mud with reduced parameters Q 1000l m, WOB 0-3 t, rpm 100-120 for the first two joints, then increase the pump rate as per the Drilling Programme. 6 At 26 hole TD, circulate a volume of mud equal to the capacity of the drilled section. 7 Perform a wiper trip to the 30 shoe and back to bottom again. Clean out any fill and circulate to condition the mud. 8 Take a directional...

Flow Checks

When required, a flow check shall be performed as follows 1 During a trip, remove the wiper rubber. 2 Pick up the drill string until the tool joint is in correct position above the rotary table and the BOP can be closed properly on the pipe body. 3 Stop the mud pumps piston and supercharged type . 4 Line up to the trip tank. Observe the trip tank indicator and visually check for flow observing the mud level in the annulus. 5 The duration of the test shall be at least 15 minutes or whatever time...

Logging While Drilling Lwd Considerations

Many factors must be considered to economically justify the use of LWD. The majority of cost savings are due to a rig time reduction associated with wireline operations, Conventional slick-line directional surveys and setup charges particularly for offshore wells . Improved rates of penetration ROP when better survey accuracy and real-time toolface data can be obtained Reduced risk of a lost well or BHA due to borehole instability High-profile exploratory wells where lwd is used for...

Taper Tap Procedure

1 Plan this operation taking into account the following factors The size of the taper tool should be selected in order to engage the fish with the middle of the tapered point. The taper taps do not allow free passage to the back-off tool. Excessive torque can damage the tapered thread and swell the top of the fish. It is nigh impossible to release the tool once engaged. For this reason its use has to be considered the last resort and only used after consultation with Eni-Agip Shore Base...

Subsea Pods

As already described, the pods contain the regulators and pilot valves required to direct the hydraulic fluid to the various stack functions. The retrievable type is the most commonly used by the industry. The retrievable male portion of the pod contains all the pod valves, regulators and the hose bundle junction box. Should a pod valve, regulator or hose bundle malfunction, it is quicker and, hence, less costly to retrieve the pod than to retrieve the riser and the lower marine riser package.

Landing The BOP Stack

1 Tension the guide lines for landing the BOP stack. 2 Run the TV camera or ROV. Focus on the lower extremities of the BOP stack. 3 Open the motion compensator. 4 Lower the BOP stack until the connector lands on the wellhead housing. Observe the landing with the TV. 5 Latch the connector. With the Motion Compensator make a pick up test of 50,000lbs 15t above the stack weight to verify the connector is correctly locked down. 6 Adjust the riser tensioners to full working tension as per the rig...

Deepest Casing Shoe

Where there is an open hole below the deepest string of casing, a cement plug shall be placed in such a manner that it extends at least 50m above and below the casing shoe. The top of the cement plug shall be located and verified by mechanical loading. If the condition of the formation makes cementing difficult, a mechanical plug may be positioned in the lower part of the casing, but not more than 50m above the shoe and a cement plug at least 20m long shall be placed on top of the mechanical...

Fail Safe Valves

These valves are usually mounted in pairs on both the choke and kill lines. They are opened hydraulically from the surface 0.6galls of fluid is typically required but once the opening pressure is released, spring force automatically forces the gate valve closed. In deep water operations, the hydrostatic head of fluid in the opening line tends to open the valve. Some designs counter this be incorporating a system which transmits seawater hydrostatic pressure to an oil chamber on the spring side...

Tripping With A Top Drive

When using a top drive, the following points should be noted a Tripping is still handled in the conventional manner. The link tilt feature can be used to tilt the elevator to the derrick man, enhancing his ability to latch it around the pipe thus improving trip times. b The link tilt has an intermediate stop which is adjustable to set the elevator at a convenient working distance from the monkey board. The intermediate stop is tilted out of the way to allow the elevator to reach the mouse hole....

Measurement While Drilling MWD

Measurement While Drilling is a technique which takes various downhole measurements and transmitting these data to the surface for decoding and display. The most common transmission media is mud pulse telemetry in which the flowing column of drilling mud is modulated periodically by some mechanical means within the downhole assembly. The intermittent pressure pulses are transmitted from downhole to the surface where they are detected by a pressure transducer mounted in the standpipe. The...

Slips Installation

1 All slips, packing elements and ring joints and their seats should be thoroughly cleaned and lubricated. 2 Make sure the hinged slips and spring retaining rings are unlatched. 4 Be sure that the correct tension is applied to the casing string. 5 Clean and inspect the ID of the base flange, polishing out any burrs or scratchers. 6 Place two wooden boards of equal thickness across the base flange so that they straddle the casing. 7 Wrap the casing slips around the casing. Latch the hinged slips...

Conductor Pipe Connections

Conductor pipe joints installed on land rigs, are usually connected by welding bevelled prepared ends of the pipes together. This is a time consuming operation that requires an average of three hours per joint. On a Jack-up, to reduce the time of the operations and when it is practicable, driveable threaded quick connectors i.e. the RL-4 and driveable squnch joint connectors such as the Fast Realising Joint i.e. the ALT-2 , should be used. a A Squnch Joint Refer to figure 4.c is a threadless...

Choke And Kill Line Outlets

The two or more outlets on the stack are usually referred to as the choke and kill line outlets and is terminology taken from land drilling operations. For floating drilling the functions of each line are interchangeable since they are manifolded at the rig floor to both the rig pumps and the well control choke. For the position of the outlets on the stack, refer to the Eni-Agip Division and Affiliates Well Control Policy in the 'Well Control Policy Manual'.

Figure A Universal Transfer Of Mercator

As a Mercator projection becomes increasingly inaccurate as one moves away from the chosen meridian, a series of reference meridians is used so that it is always possible to use a map with the reference meridian close to the place of work. The reference meridians used are 6 degrees apart providing 60 maps, called zones, to cover the whole world. The zones are numbered 0 to 60 from west to east with zone 31 having the 0o meridian Greenwich on the left and 6o E on the right. Each zone is further...

Gyro Single Shot Surveys

Gyro single shot surveys are carried out on wireline. Since gyroscopes are delicate instruments, running speeds should be within that recommended and the tool stopped and started off gently. The gyro instrument has the same mule shoe feature as the magnetic single shot used for orientation and, although it uses a different system, the data obtained is the same, i.e. hole direction, inclination and tool face . The maximum depth to which they can be effectively run is approx. 1,300ft about 400m....

Installation Patterns For Mechanical Cementing Aids

The selection of the proper installation pattern for mechanical cementing aids i.e. centralises, scratchers, turbolisers, etc. is essential to optimise casing running and cementing results. Cementing aids and their installation pattern are a function of operational conditions and cementing objectives. Because of these variable factors, pattern philosophy is different from case to case. The Drilling Programme must specify type, quantity and installation pattern of mechanical cementing pieces,...

Post Plug Pattern

This pattern Refer to figure 12.b is recommended throughout the entire cement column to promote improved cement-to-formation bonding in strings where casing can be reciprocated in 30 to 40ft cycles. The post-plug pattern uses at least one centraliser per joint and free-to-move scratchers, separated by stop collars installed approximately 10ft 3m apart. The Modified Post-Plug pattern requires two centralisers per joint in conjunction with multiple scratchers and stop collars placed 5ft 1.5m...

Drilling With Oilbased

The following issues should be considered when drilling with oil base muds a To avoid pollution, precautions shall be in place drains from the rig floor and shale shakers, cuttings treatment, etc. in order to avoid environmental spillage. b The safety of the crew shall always be paramount to prevent oil mud skin contact and accidents such as tripping, falling, hand crushing, etc. c Maintain the cleanliness of the rig. d Oil resistant equipment various pack-off, seals on mud pits, etc. must be...

Casing hanging after the second stage while Waiting On Cement WOC

When a cement job programme does not require the return of the slurry up to surface, the hanging is performed after the second stage cement slurry thickening time, then it is possible to disconnect the BOP stack maintaining annulus control. In deep wells, where the casing string must be cemented to surface, it may become difficult to work on the wellhead when the slurry is nearly hardened, for the following reasons The casing is often out of centre and it is difficult and time consuming to...

Drilling Ahead In HPHT Formations

The intention of this procedure is to maintain full pressure control during drilling operations and have the bit as close as possible to bottom in case a kick should occur. At the same time have the kelly valve close to the rotary table in order to carry out jobs which require a tool joint near the rotary table, e.g. installation of high pressure circulation lines, wireline lubricator, etc. 1 Make-up a kelly cock 15,000psi to the single in the mouse-hole. The valve is to be in the open...

Contractor Performance

There are two forms for the reporting of contractors performance. Report FB-01 is for reporting of malfunctions and failures in services and equipment. Report FB-02 is for documenting a contractors performance in relationship to the contract conditions. These should be completed giving an explanation of problems encountered and suggestions for performance improvement. Both of these forms must be completed in a timely manner at the end of the contractor's operations or at the end of the well,...

Gyrocompass North Seeking Gyroscope

These instruments use the principle of earth rate gyro compassing to define true azimuth and inclination in near vertical parts of the borehole. Then, as the hole builds angle to above 15o, it switches to a continuous integrating mode. This dual mode makes the tool accurate in either vertical and deviated borehole where it eliminates the inaccuracies that gyrocompass based instruments have at high latitude, high inclination or in the East West axis. The rugged construction makes these tools...

Accumulators

Accumulators are used to store hydraulic fluid under pressure. As much accumulator volume as possible is located on the subsea stack in order to reduce operating time and also to enable them to act as a surge chamber for the annular preventers. Surface accumulators are pre-charged with nitrogen to 1,000psi 70kg cm . Subsea accumulators should be precharged with nitrogen to 1,000psi 70kg cm2 45psi per 100ft 10.3kg cm2 per 100m of water depth to compensate for the hydrostatic head of sea water....

Top Drive Drilling Systems

The Top Drive Drilling System Refer to figure 4.h and figure 4.i consists of a drilling drive motor that connects directly to the top of the drill string. The motor, which provides the similar torques and speeds found in most independent rotary drive systems, is mounted to the rig's conventional swivel and is most commonly a DC drilling motor but hydraulic versions are also available. The drill pipe is rotated by the motor through reduction gearing. The swivel attaches to the travelling block...

Running The Bop And Riser

Before running the BOP stack check the weather forecast and refer to the 'Rig Operations' manual for the maximum vessel motion heave, roll and pitch for running BOP. Running procedures vary from rig to rig due to the specific design of the stack and to the handling system gantry cranes, fork lifts, trolleys, etc. used for moving the BOP in and out of the moonpool area. There are also a variety of ways to land the BOP stack. For this reason provision of detailed procedures is not possible...

Techlube Tl Thread Coumpound

Shell France Modified Thread Compound Jet-Lube Kopr-Kote made in UK 0,85 Jet-Lube TF-15 made in UK 0,90 Jet-Lube TF-25 made in UK 0,80 Jet-Lube TF-65 Pb made in UK 0,70 Jet-Lube TL-60 Z 15 made in UK 0,80 Research Laboratories API Modified HP 300 0,85 Shell HP API Modified Shell Oil Co. Code 72732 0,80 Shell HP API Modified Shell Canada Ltd Code 504-599 0,80 Techlube API Modified Thread Compound 0,70 Jet-Lube SS 30 made in UK 1,15 Bakerlok Thread Locking Compound 1,60 Gelokote T 7.285 Thread...

Cameron

The Cameron U-type preventers use a wedge-lock device Refer to figure 5.b to accomplish this feature. It consists of a tapered wedge, hydraulically operated, which moves behind the tail rod of the ram operating piston when the ram is in the closed position. Since it can only move when ram lock pressure is applied and the ram is fully closed, all the ram lock cylinders on the stack are connected to just two common control lines, lock and unlock. Ram lock pressure is activated from the surface as...

Casing Spool Installation

1 Clean the ring grooves on the bottom flange of casing spool and on the base flange, as well as the restricted packing bore of the casing spool. 2 Oil the secondary packing and the restricted packing bore of the casing spool. 3 Fill the void area with oil around the primary and secondary packing group. 4 Place the metal ring joint in its groove. 5 Align the bolt holes on the casing spool with the bolt holes on the base flange. 6 Lower the casing spool over the secondary packing assembly being...

Running Of Casing

1 Run and cement in the single or dual stage 7 casing Refer to the Casing Running and Cementing section 12 . Wait on cement. 2 Hang the 7 casing on the second intermediate casing spool giving it the additional tensile load calculated as per the 'Casing Design Manual' STAP P1M6110-8.3.4 , if required, and cut the 7 casing. 4 Nipple up the tubing spool and test it. 5 Re-install the BOP stack replacing the 5 lower pipe rams with 5 variables or 3 2 rams and test them as per the 'Well Control Policy...

Differential Sticking Causes

This phenomenon can occur, where there is case of high differential pressure between the mud hydrostatic pressure and the formation pore pressure. Some indications of pipe becoming differentially stuck may be The string becomes stuck in front of a porous formation. Pipe has not been moved for a period of time before getting stuck i.e. during a pipe connection. Circulation is free with no pressure variation. A normal amount of cuttings is observed at the shaker.

Horizontal Departure

Vertical Section The projection of the horizontal displacement onto a vertical plane usually along the target direction. Lead Angle When drilling with rotary drilling assemblies there is a tendency for the hole to 'walk to the right'. Turbine drilling assemblies have the opposite tendency, that is 'walk to the left'. The lead is the angle to be applied to the project direction at kick-off to correct the walking tendency of the drilling assemblies.

Fishing Procedures Overshot

1 Plan the operation taking into account the following factors The catching action of the tool will stress the fish neck in words. A regular, smooth shape of the fish neck is necessary for a successful operation. Jarring is only possible only using type SFS, FS and XFS overshots. If the fish diameter is near the maximum catch or size, a spiral grapple is recommended. On the other hand, if the fish diameter is considerably below the maximum catch size, a basket grapple is preferable. If the hole...

Steering Tool with mud motor

Steering tools use a system of magnetometers and accelerometers to measure the Earth's magnetic field and gravity in order to determine inclination and direction. The tool is run on a conductor wireline which provides power for the sensors and returns the signal to the surface computer where it is decoded and relayed to the rig floor read out. The tool may be operated on one of two modes displaying tool face with respect to North Magnetic Tool Face or relative to the high side of the hole...

Drill Pipe Fatigue

If a programme is designed in such a way that drill pipe damage is avoided, while drilling the hole, then the hole will be acceptable for conventional casing, tubing and production string designs, as far as dog-leg severity is concerned. A classic example of the severe dog-leg condition which produces fatigue failures in drill pipe can be seen in figure 8.a. The stress at point B is greater than the stress at point A but as the pipe is rotated, point A moves from the inside of the bend to the...

Slip Joint

The slip joint, or telescopic joint consists of an outer barrel connected to the riser with a polished steel inner barrel connected to the diverter ball joint. Rubber packing elements seal the annular space between the two barrels whilst still allowing the inner barrel to 'scope' up and down. The packing is usually actuated by air and or hydraulic fluid pressure which is adjusted so that a small amount of mud is able to leak past the seal to provide lubrication. Split packings are used so that...

Coring In Deviated Holes

In deviated holes certainly in angles over 20o , coring is more difficult because of the additional forces caused by the weight on bit, the weight of the core barrel and of the drill collars at such angles. These gravity forces will bend the drill collars and core barrel. As a result the inner barrel will also rotate and the bit will start to wobble. This again will result in poor recovery and unequal wear of the core head. Also the hole angle and direction could be affected. In order to...

Horizontal Displacement

Using UTM co-ordinates Refer to Figure , displacement and direction can be determined with trigonometry as shown in the following example. UTM co-ordinates of rig UTM co-ordinates of target Absolute difference in Eastings Absolute difference in Northings 410,261.0 E 6,833,184.2 N 412,165.0 E 6,834,846.0 N 1,904.0m 1,661.8m Figure 9.D - Example Calculation Of Horizontal Displacement Figure 9.D - Example Calculation Of Horizontal Displacement origin used may correspond to wellhead or slot in a...

Magnetic Multishot Surveys

Magnetic multishot surveys are generally run prior to running casing as a check on the single shot surveys taken while drilling. This survey may be run either as an inrun or running outrun survey, although it is generally run on the outrun wiper trip before casing. This gives an opportunity for the instrument to be retrieved at the casing shoe and checked whilst the trip back to bottom is being made. A second opportunity is then available if necessary. As the name implies, the magnetic...

Gyro Multishot Surveys

The gyroscopic multishot is the survey tool for surveying extended intervals inside casing or drill pipe without a non-magnetic drill collar. The tool comes in two sizes. The smaller one can be run in completed wells or through drill pipe. The larger one is a more rugged tool and is used to run surveys inside casing. Depending on the length of survey run, it will be a number of hours before the calculated survey data are available. Gyro multishot drifts are the same as that of the single shot...

Variable Rams

In order to provide more flexibility and perhaps avoid having to pull the stack to change pipe rams when drilling is to continue with 31 2 drill pipes, variable bore pipe rams can be used. These are available in a variety of size ranges. They are capable also of being used for hang-off purpose though the weight they can support depends on the size of pipe they are closed around. However, variable bore rams are not recommended for stripping operations or for high temperature application.

Jarring Procedure

1 Jarring should be done with a Kelly or Top Drive. If the use of a Kelly is not possible, secure the elevator latch by using a piece of rope or chain. 2 Prior to jarring check the drill line sensor. Ensure the weight indicator readings are accurate and that the Dead Line Anchor is secure and free of debris. Check the derrick and all equipment for any loose items. 3 When jarring, the drill floor must be cleared of all non-essential personnel. 4 Prior to jarring, mark the drill string at the...

Leak Off Test Procedure

A Leak-Off Test LOT will be performed On Wild-Cat wells at each casing shoe after setting the surface casing. LOTs are also recommended to be carried out on both appraisal and development wells. Leak Off Test and Formation Integrity Test FIT , also termed the Limit Test, are for formation strength pressure tests made just below the casing seat prior to drilling ahead. Investigate the cement seal around the casing shoe which should be at least as high as the predicted fracture pressure for the...

Temporary Abandonment Procedure

It is assumed that the well has been plugged and secured and that wellhead and all surface equipment have been removed. The casing landing strings are recovered. Retrieve the last casing running tool and install the appropriate corrosion cap. Repeat the procedure in the same way for the outer casing. In this way the next largest casing will provide adequate guidance for the corrosion caps. Casing spears are used to apply torsion at the very top of each casing landing string for backing out the...