Good Salt Clav In Salt Water Approximates The Bentomte Vielo Curve In Fresh Water

Typical clay yield curves. (From Principles of Drilling Fluid Control. Courtesy of Petroleum Extension Service, University of Texas, Austin.) mers) are added to salt water, or to salt-contaminated muds. Cellulosic, poly-acrylic and natural gum polymers are also used in low-solid muds to help maintain hole stability and to minimize dispersion of drill cuttings into the mud. These polymers consist of long chains of unit cells which are adsorbed on the surface of the cuttings,...

Chapter Introduction To Drilling Fluids

The successful completion of an oil well and its cost depend to a considerable extent on the properties of the drilling fluid. The cost of the drilling fluid itself is relatively small, but the choice of the right fluid and maintenance of the right properties while drilling profoundly influence total well costs. For example, the number of rig days required to drill to total depth depends on the rate of penetration of the bit, and on the avoidance of delays caused by caving shales, stuck drill...

Composition of Drilling Fluids

Drilling fluids are classified according to their base Water Base Muds. Solid particles are suspended in water or brine. Oil may be emulsified in the water, in which case water is termed the continuous phase. Oil Base Muds. Solid particles are suspended in oil. Water or brine is emulsi fied in the oil, i.e., oil is the continuous phase. Gas. Drill cuttings are removed by a high velocity stream of air or natural gas. Foaming agents are added to remove minor inflows of water. In water base muds...

Preface

This new edition brings up to date the concepts and techniques discussed in the earlier editions of this classic work. Major advances have been made in the control of borehole stability, induced fracturing, transport of cuttings in inclined holes, and stuck pipe, which are described in detail. Other subjects are touched on briefly, and 204 new references have been added. Chapter 1 has been largely rewritten for the benefit of those who are not directly responsible for drilling fluids but are...

References Foam Drilling

Functions of Drilling Fluids, 1 Composition of Drilling Fluids, 2 Properties of Drilling Fluids, 6 Drilling Fluid Selection, 19 Mud Handling Equipment, 28 Optimization, 33 References, 34 Water-Base Drilling Fluids Technology, 38 Removal of Cuttings, 38 Pressure Control by Mud Density, 41 Birth of the Mud Industry, 42 Rapid Growth of the Mud Industry, 44 Development of Mud Types or Systems, 50 Corrosion Control, 59 Different Types of Fluid for Different Drilling Functions, 62 Oil-Base Drilling...

Info

Normally pressured formations, which have a self-supporting structure of solid particles so the pore pressure depends only on the weight of the overlying pore fluids , and abnormally pressured or geopressured formations, which are not fully compacted into a self-supporting structure so the pore fluids must bear the weight of some or all of the overlying sediments as well as the weight of the overlying fluids . The hydrostatic pressure gradient of formation fluids varies from 0.43 psi ft to over...

Drilling Fluid Selection

Saturated Saltwater Drilling Fluid

Over the years a considerable number of drilling fluid formulations have been developed to suit various subsurface conditions. Selection of the best fluid to meet anticipated conditions will minimize well costs and reduce the risk of catastrophes such as stuck drill pipe, loss of circulation, and gas kicks. Consideration must also be given to obtaining adequate formation evaluation and maximum productivity. The different types of drilling fluids that are available have been summed up by...

Mud Handling Equipment

Drilling equipment capability may affect the drilling fluids program. Inadequacies in pumps, mixing equipment, or solids-removal facilities will be likely to increase consumption of materials, and sometimes the preferred program must be modified to compensate for deficiencies in the equipment. The importance of the drilling equipment to the success of the mud program deserves a more extensive treatment than can be given here. Hutchison and Anderson summarize in tabular form Table 1-4 the...

Rapid Growth of the Mud Industry

Filter Press Design Drilling Fluid Cap

After the California Division of Oil and Gas Operations was established in 1915, the employment of engineers in the oil industry began to increase. Usually, the engineers were concerned only with production and little attention was given to drilling.20 Several discussions on the use of mud were reported, however, in Summary of Operations California Oi Fields2 J and some of these were reprinted in oil industry publications.22 The mechanism of wall building in the drill hole was studied to some...

Waterbase Drilling Fluids Technology

Ancient Chinese Rotary Drill

If drilling fluid is defined as a material employed to aid tools in the creation of a borehole, the use of drilling fluids far antedates the petroleum industry. Water, the principal constituent of the majority of drilling fluids in use today, was the first drilling fluid. As early as the third millenium in Egypt, holes up to twenty feet deep were drilled in quarries by hand-driven rotary bits. J.E. Brantly, the recognized authority on the history of drilling, concludes that water probably was...

Pressure Control by Mud Density

Cable Tool Drilling Rig Sampling

A serious problem the enormous waste of natural gas in drilling by the cable-tool method in Oklahoma led to the general acceptance of mud laden fluid as a means of controlling pressure. In May 1913, Pollard and Heggem11 11 of the U.S. Bureau of Mines, demonstrated the practicality of Figure 2-3. This mud mixer used shortly after the turn of the century served the same purpose as today's mixers. From Gray,89 World Oil. Figure 2-3. This mud mixer used shortly after the turn of the century served...

Salt Water Muds

Filter Cake Drilling Fluids Pictures

Early field experience, as well as laboratory studies, established that bentonite was the most practical material for improving the viscosity and wall-building properties of fresh-water muds. As dissolved salt content increased, however, bentonite became progressively less effective. In saturated salt water, bentonite did not swell, and contributed little toward reduction of filtration. To thicken salty muds, bentonite was mixed into fresh water and the resulting thick slurry was added to the...

Hole Stabilization Wall Building

An application for a U.S. patent, filed in 1887 by M.J. Chapman, proposed a stream of water and a quantity of plastic material, whereby the core formed in the casing will be washed out and an impervious wall be formed along the outside. He suggested clay, bran, grain, and cement. Here was another function of the drilling fluid to plaster the wall of the hole and reduce caving tendencies. Figure 2-2. Sweeny's rotary drill of 1866 had some features in common with rigs of today. Courtesy of NL...

HighpH Muds

In the 1930s the most popular thinning agent for muds was quebracho extract. This vegetable tannin, derived from a South American hardwood tree, has a deep red color when dissolved with caustic soda. High concentrations of caustic-quebracho produced high-pH mud which had some desirable features in shale drilling in particular, low gel strength and great tolerance for shale solids. 5 5 From the high-pH red mud came the red lime mud, or lime mud, that was consistently the most popular mud in the...

Oilbase Drilling Fluids Technology

Oil-base drilling fluids have been developed to overcome certain undesirable characteristics of water-base muds. These deficiencies are primarily due to the properties of water specifically, its abilities to dissolve salts to interfere with the flow of oil and gas through porous rocks to promote the disintegration and dispersion of clays and to effect corrosion of iron. In addition to providing a means for avoiding these objectionable features of water muds, oil muds offer potential advantages...

Oil Emulsion Muds

Pumping Water Into Oil Bed

At about the time that lime muds came into use in Gulf Coast drilling, oil emulsion mud was recognized as a method of making a good mud better. Much earlier, oil had been used to loosen stuck drill pipe and to slick up the hole before running casing25. Drillers in the Oklahoma City field 1934 -1936 added crude oil to mud to reduce sticking of pipe, and in 1937 a drilling contractor in Pottawatamie County, Oklahoma, noted a faster drilling rate after adding oil.66 By 1950 numerous reports of...