Drilled Solids

Mud solids include particles that are drilled from the formation, material from the inside surface of the hole and materials that are added to control the chemical and physical properties of the mud, such as weight material. Drilled solids' particles are created by the crushing and chipping action of rotary drill bits. Additional solids enter the well bore by sloughing from the sides of the open hole. The unit of measurement generally used to describe particle size is the micron (p). A micron...

E

A device using a high velocity jet to create a vacuum which draws in liquid or dry material to be blended with drilling mud. The portion of a screen surface available for solids separation. Any rubber or rubber-like material (such as polyurethane). The pressure created by a given height of fluid. See related term HEAD. A substance used to produce an emulsion of two liquids which ordinarily would not mix. A substantially permanent mixture of two or more liquids which do not normally dissolve in...

Reduced Dilution Requirements

A common method of trying to offset the build-up of drilled solids is the addition of more liquid. This is known as dilution and does not remove cuttings but reduces (or dilutes) their concentration in a drilling mud, thereby reducing the percent of total solids in the mud. However, it is important to note that dilution is expensive. Every barrel of dilution water (or oil) added requires an additional amount of chemicals, barite or other materials in order to maintain desired mud properties....

Gel Strength

Gel Strength is a function of a mud's inter particle forces and gives an indication of the amount of gelation that will occur after circulation ceases and the mud remains static for a period of time. Typically, gel strengths are reported for initial and 10-second gel strength. A large deviation of these two figures may indicate progressive gels, that is, gelation structures that gain strength over time. Gel strength is also measured with a viscometer and expressed in lbs 100 ft2....

Density Mud Weight

Density is a measure of the weight of the mud in a given volume, and is frequently referred to as mud weight. The instrument used to measure density is the mud balance (see Figure 1-6). The instrument consists of a constant volume cup with a lever arm and rider calibrated to read directly the density of the fluid in lbs gal (water 8.33 lbs gal) and pressure gradient in psi 1000 ft (water 433 psi 1000 ft) or pounds per cubic foot (water 62.4 lbs ft). Effect of Particle Size and Shape on Surface...

Roto Sep Centrifuge

The Roto-Sep Centrifuge is a perforated rotor design to remove undesirable fine solids from weighted drilling fluids. The rotating separation chamber increases solids settling rate to remove these fine solids and recover barite with up to 92 efficiency. Available in skid- or trailer-mounted units, the Roto-Sep provides slurrified solids, thus allowing the unit to be located a distance away from the solids return tank and simplifying installation.

ATL Screen Separator

Designed for smaller drilling rigs and workover units, the ATL-1200 combines the performance of the ATL-1000 Separator with a lower weir height in a single, compact unit that routinely out-performs larger shakers. The flat (no crown) screen deck reduces liquid loss down the sides of the screens and maximizes usable screen area. The ramp-slope design allows the feed end screens to be operated downhill with the discharge end screens flat for maximum conveyance of sticky solids. With the feed end...

Standard Calculations

Capacity of annulus in bbl ft (hole size)2 - (pipe OD)2 * 0.00097 Approximate capacity of hole in bbl 1000 ft (diameter of hole)2 Approximate pipe displacement, bbl 100 ft Weight of pipe (lb ft) * 0.0364 Pit volume in cu ft Length * Width * Depth Hole volume in bbl hole capacity(bpf) * depth(ft) - pipe displacement (bbl) Annular volume in bbl hole volume - capacity and displacement of drill pipe Total Volume hole volume + pit volume Pump output in bpm bbl stroke * strokes minute . , , . pump...

Percent Open Area

Percent Open Area is the amount of the screen surface which is not blocked by wire. The greater the wire diameter of a given mesh screen, the less open space between the wires. For example, a 4 mesh screen made of thin wire has a greater percent of open area than a 4 mesh screen made of thick wire (see Figure 3-8). The higher the percent of open area of a screen the greater its theoretical throughput. Open area can be increased for a given mesh by using smaller diameter wire, but at the...

Solids Control Performance Evaluation

There are several methods used to determine economic performance. This appendix describes a method to compare the cost of dilution versus mechanical removal. It utilizes the concept of a dilution factor (the amount of mud required to maintain a given solids concentration for every barrel of solids that remain in the mud) to determine dilution requirements. This method may be used to determine economic efficiency of any type of solids control equipment. Note Effluent is defined as the process...

Separation By Settling And Centrifugal Force

Using vibrating screens to remove drilled solids from mud uses only one characteristic of solids particles their size. Another factor which affects separation is particle density. Solids control devices which take advantage of both particle size and particle density speed up the settling process by application of centrifugal force. These devices utilize Stoke's Law as the basis for their operation. Stoke's Law defines the relationship of factors governing the settling velocity of particles in a...

Separation Process

A Decanting Centrifuge is so named because it Decants, or removes, free liquid from separated solids. A decanting centrifuge consists of a conveyor screw inside a rotating bowl, see Figure 3-26. Decanting centrifuges operate on the principle of exposing the process fluid to increased G-forces, thus accelerating the settling rate of solids in the fluid. A rotating bowl creates high G-forces and forms a liquid pool inside the bowl. The free liquid and finer solids flow toward the larger end of...

Shape Of Opening

Shape of Opening is determined by the screen's construction. Screens with the same number of horizontal and vertical wires per inch produce square-shaped openings and are referred to as Square Mesh screens. Screens with a different number of horizontal and vertical wires per inch produce oblong or rectangular shaped openings and are referred to as Rectangular (or Oblong) Mesh screens. This is illustrated in Figure 3-9. Use of a single number in reference to a screen usually implies square mesh....

High Efficiency Solids Removal Systems

The goal of high efficiency solids removal systems, often called closed loop systems, is to limit waste discharge to disposable solids and clear water. These systems combine the equipment found in Section 3.12 with chemically-enhanced solids removal and specialized solids handling techniques. The water is often recycled on location for building new mud, as rig wash water, or used for irrigation. A closed loop system often includes multiple shale shakers and centrifuges to achieve a high...

Vacuum Degassers

The DG-5 500 gpm and DG-10 1000 gpm vacuum degassers have been rated by an independent study as the best-performing degassers for drilling fluid service. These degassers are compact, low-profile, and provide maximum release and removal of entrained gas by flowing the gas-cut fluid in very thin sheets across a series of stacked plates. While an eductor jet removes the degassed mud, a rugged, H2S-rated vacuum pump provides positive removal of gas. There is no remixing of mud and gas as found in...

Field Calculations to Determine High and Low Gravity Solids Discharge

Use a one-quart container and wristwatch to determine how many seconds R it takes for one quart of solids to be discharged. 2. Use a mud balance to obtain the density D of the sand slurry in pounds per gallon. 3. Retort the sand slurry to determine the volume fraction solids Vs and the volume fraction liquids Vi 4. Use the following equations to calculate the rate of solids removed in pounds per hour. A. Total pounds per hour Solids Removed D - 8.34 Vi 900 B. Average Specific Gravity of...

Table Of Contents

1.0 DRILLING MUD AND MUD 1.1 Functions of Drilling 1.2 The Nature of Drilled 1.3 Properties of Drilling 1.4 Types of Drilling 2.0 BENEFITS OF SOLIDS REMOVAL BY MECHANICAL SEPARATION 2.1 2.1 Reduced Total Solids 2.2 Reduced Dilution 3.0 MECHANICAL SOLIDS CONTROL AND RELATED EQUIPMENT 3.1 3.1 Particle Classification and Cut 3.2 Separation by Vibratory 3.3 Shale 3.4 Mud 3.5 Separation by Settling and Centrifugal 3.6 Sand 3.10 Decanting 3.11 Auxiliary 3.12 Unitized 3.13 Rig Enhanced 3.14 High...

Tandem Screen Separator

The dual-deck Tandem Screen Separator is designed to process high volumes between 20 and 120 mesh. The horizontal screen deck and circular motion provide excellent conveyance of solids, especially sticky clays. High capaci- ty and efficient separation are achieved because the top screen separates large solids from the mud and improves the separating performance and screen life of the bottom screen. The reliability, low maintenance requirements and quiet, dependable operation have made these...

Desilters

Available to process 60 gpm to 1440 gpm, Brandt EPI Desilters offer excellent high temperature tolerance, resistance to abrasion, and low-cost replacement. They incorporate involute feed entry, preferred flanged designs for tight, leak-proof performance, all-polymer construction, and standard Victaulic connections. These features make them the preferred choice for both contractors and operators. Each desilter cone is 4 diameter with an adjustable solids discharge apex for maximum solids...

Cut Point

How Create Cut Point Curve

Notice the removal range, or Cut Point, is given as a range of the particle size removed. Mechanical solids control equipment classifies particles based on size, shape, and density. It is typical to refer to particles as being either larger than the cut point of a device oversize or smaller than the cut point under-size . Figure 3-2 shows a typical cut point curve. The cut point curve represents the amount of solids of a given size that will be classified as either oversize or undersize....

Rope Discharge

Cyclone Roping Underflow

Hydrocyclones should not be operated in rope discharge because it will drastically reduce the cone separating efficiency. In a rope discharge, the solids become crowded at the apex, cannot exit freely from the underflow, and become caught by the inner spiral reporting to the overflow. Solids which otherwise would be separated are forced into the overflow stream and returned to the mud system. This type of discharge can also lead to plugged cones and much higher cyclone wear. While a spraying...

Hydrocyclone Cut Point

Particle separation in cyclones can vary considerably depending on such factors as feed head, mud weight, percent solids, and properties of the liquid phase of the mud. Generally speaking, increasing any of these factors will shift the cut point curve to the right, increasing the size of solids actually separated by the cyclone. By itself, the cut point does not determine a cyclone's overall efficiency because it ignores the liquid loss rate. The amount of fluid in the cone underflow is...

Drying Shakers

A drying shaker, or dryer, is a vibrating screen separator used to remove free liquid from cuttings prior to discharge and recover the liquid for re-use. Drying shakers are usually installed to process the cuttings discharged from primary scalping and or fine screen shakers. A typical drying shaker is a linearmotion, multi-screen unit, with a feed hopper in place of the traditional back tank. Drying shakers are optimized to provide maximum retention time and cuttings dryness. Large hole sizes...

Mud Agitators

Brandt Nov Agitator

Brandt EPI MA Series mechanical agitators are available from 3 HP to 25 HP, with flat or canted impeller blades for complete mixing action. Their low profile minimizes headroom requirements and provides stability and safety. Brandt EPI agitators use a single-reduction, worm worm gear drive for higher efficiency, dependable service, and smooth vibration-free operation. The Agitator Sizing Chart for Drilling Muds, another Brandt EPI innovation, simplifies proper agitator sizing and selection, and...

Threedimensional Screen Panels

To increase screen capacity without increasing the size or number of shale shakers, three-dimensional screen panels are available. The design of these 3-D, Pinnacle shaker screens Provides even distribution of fluid across the screen surface Eliminates unwanted fluid loss near the screen edges Improves dryness of solids discharge Allows the use of finer screens 3-D screen panels increase the usable screen area of a screen panel by corrugating the screen surface, similar to the surface of a...

Rig Shakers

Possum Belly Rig

The rig shaker is the simpler of two types of shale shakers. A rig shaker also called Primary Shale Shaker or Coarse Screen Shaker is the most common type of solids control equipment found on drilling rigs. Unless it is replaced by a fine screen shaker, the rig shaker should be the first piece of solids control equipment that the mud flows through after coming out of the hole. It is usually inexpensive to operate and simple to maintain. LIQUID and FINE-SOLIDS DISCHARGE CHUTE LIQUID and...

Hydrocyclones

Vortex Nozzle

Hydrocyclones also referred to as cyclones or cones are simple mechanical devices, without moving parts, designed to speed up the settling process. Feed energy is transformed into centrifugal force inside the cyclone to accelerate particle settling in accordance with Stoke's Law. In essence, a cyclone is a miniature settling pit which allows very rapid settling of solids under controlled conditions. Hydrocyclones are important in solids control systems because of their ability to efficiently...

Dewatering Units

Brandt EPI offers several models of dewatering units, from simple, skid-mounted metering pump and tank modules, to the DWU-250 Dewatering Unit. The DWU-250 is a self-contained, portable system that includes all mixing and polymer aging tanks, metering pumps, piping and connection points, controls, and quality check points in a modular, weatherized container enclosure. The DWU-250 is used with one or more decanting centrifuges as part of the Chemically-Enhanced Dewatering process. The climatized...

Fine Screen Shakers

The fine screen shaker is the more complex and versatile of the two types of shale shakers. Fine screen shakers remove cuttings and other larger solids from drilling mud, but are designed for greatly improved vibratory efficiency over simple rig shakers. They are constructed to vibrate in such a way that they can use screens as fine as 150-200 mesh and still give reasonable screen life. They are versatile pieces of equipment and can operate on all types of mud. Figure 3-15 shows the range of...

Blue HexSM Screen Panels

Brandt EPI's exclusive Blue HexSM screen panels are flat there is no crown. This design increases usable screen area and reduces liquid loss along the sides of screen panels. Blue HexSM screen panels eliminate the leading causes of screen failures screen flex, propagation of tears, improper tensioning, blinding and contamination from process fluids. Blue HexSM screens are available in single- and multi-layer configurations. The wirecloth is factory pre-tensioned for longer screen life. These...

Closed Loop Processing Systems

All Brandt EPI equipment can be integrated into systems designed for specific applications. We have over 20 years' experience designing, manufacturing, and operating systems for Closed Loop processing of drilling fluids, dewatering systems, cuttings wash systems, product classification systems, and other waste reduction management systems. Brandt EPI equipment is currently in service throughout the world, providing excellent results in land and offshore installations, remote areas, processing...

Glossary

The liquid film that adheres to the surfaces of solids particles which cannot be removed by draining, even centrifugal force. The mechanical incorporation and dispersion of air into a drilling fluid system. If not selectively controlled, it can be very harmful. See Preferred Term AERATION AIR LOCK A condition causing a centrifugal pump to stop pumping due to a ball of air or gas in the impeller center that will not let liquid enter usually caused by aeration . The distance from the mean...

Sand Traps

Mud Sand Trap

A sand trap Figure 3-19 is a settling tank, usually the first compartment of the first pit in the mud system. A shale shaker would normally sit on top of the sand trap and discharge into it. Sand traps can serve an important role in solids control by protecting downstream equipment against the results of torn shale shaker screens or by-passed shakers by removing large particles which could plug cyclones or other equipment downstream. In normal operation they also play a minor solids removal...

HS High Speed Decanting Centrifuge

The HS5200 is a third-generation high-speed decanting centrifuge capable of 4000 Gs and 4200 RPM operation. Based on the proven HS3400 design, the HS5200 has a 16 x 49.5 contour bowl and high torque drive system for higher capacity and sharper separations up to 250 GPM and 8 TPH. The HS5200's all-hydraulic drive system can be easily adjusted for optimum performance in all fluid processing conditions. Main bowl speed is infinitely variable up to the maximum 4200 RPM, and the bowl conveyor...