R

Rh Radius of bob in rotary viscometer A. Inner radius of rotor in rotary viscometer > ,. Terminal velocity of a particle in a still liquid v, Net velocity of a particle in a rising column of liquid vs Slip velocity of a particle in a rising column of liquid YP Yield point, as determined in a two-speed rotary viscometer yn Shear rate at pipe wall 0 Dial reading on rotary viscometer Hp - Plastic viscosity of a Bingham plastic J, Effective viscosity of a non-Newtonian fluid To Shear stress at...

600 340

From AIM RP46, First Edition (Nov. 1966) American Petroleum Institute, Dallas. The aniline point determination indicates the relative aromatic content of an oil. The aniline point is the lowest temperature at which equal volumes of aniline and oil are completely miscible. Oils having a high aromatic content have a low aniline point. An aniline point of 150 F (65 C), or higher, indicates a low aromatic content and consequently the oil is less likely to damage rubber with which it comes into...

S

Effect of field mud filtrates on oil permeability of Paloma Field (Stevens sand) cores. (From Novak and Krueger. Courtesy API.) Figure 10-14. After oil has replaced aqueous filtrate, remaining fines are immobilized in connate water- (From MueckeJ7 Copyright 1978 by SPE-AIME.) Figure 10-14. After oil has replaced aqueous filtrate, remaining fines are immobilized in connate water- (From MueckeJ7 Copyright 1978 by SPE-AIME.) reservoir, and the rate of production. Field studies have...

Synthetic Water Dispersible Polymers

Numerous completely synthetic water-dispersible polymers have been made from monomeric materials.* A very broad range in composition and properties is possible in forming homopolymcrs. copolymers, and copolymers whose homopolymers are not water soluble. Many products are synthesized by direct polymerization some by a second reaction. As an example of polymer synthesis, consider acrylic polymers consisting of carbon, hydrogen, oxygen, and nitrogen. Many water soluble...

Birth of the Mud Industry

The use of barite in oil well drilling attracted the interest of Phillip E. Harth, sales manager for National Pigments and Chemical Company, a subsidiary of National Lead Company and a producer of barite for the pain t industry. Mr. Stroud16 accepted Mr. Harth's offer of assistance in securing a patent on the addition of heavy minerals to mud in return for exclusive sales rights under any such patents. Paint-grade barite from the St. Louis, Mo. plant was sold for oil well use under the brand...

Common Inorganic Chemicals

The drilling fluids industry provides an outlet for a number of common inorganic chemicals. Some of these chemicals are used in the preparation of commerical products, and their identity is lost. The chemicals listed here are only those sold by most mud suppliers2 ' Estimates of the quantities used in 1978 are, in many cases, little more than guesses. Several factors contribute to this uncertainty. For example, some users may buy alkalies from the manufacturer, or from a chemicals dealer,...

The Filtration Properties Of Drilling Fluids

In order to prevent formation fluids from entering the borehole, the hydrostatic pressure of the mud column must be greater than the pressure of the fluids in the pores of the formation. Consequently, mud tends to invade the permeable formations. Massive loss of mud into the formation usually does not occur, because the mud solids are filtered out onto the walls of the hole, forming a cake of relatively low permeability, through which only filtrate can pass. Muds must be treated to keep cake...

3 3 5 35

Effect of specific gravity of weighting material on the solids con centration of weighted mud. the surroundings. Consideration of these factors, along with chemical inertness and specific gravity, has made barite the only mineral now used in significant quantities in the United States to raise the density of muds. Characteristics. Pure barite (barium sulfate, BaS04) contains 58.8 barium and has a specific gravity of 4.5. Commericial barite, sometimes called heavy spar or tiff, is...

X

Subsequent work, however, has shown that adsorption of surfactants can either increase or decrease the hardness of crystalline surfaces, depending on the nature and amount of the surfactant and on the particular crystalline substance.22, 23, 24' 25, 26, 27 Moreover, surfactants that decreased the hardness, or decreased the triaxial yield strength only when the failure was ductile, increased the penetration rate of drag bits, but decreased that of roller and diamond bits. On the other hand,...

Thinners Mud Conditioning Agents

The substances discussed in this section have traditionally been called thinners. Thinners are added to mud to reduce flow resistance and gel development, and that was the original purpose in applying these materials. Experience has shown, however, that some of these so-called thinners perform other important functions, frequently of greater significance than improving the flow properties of the mud. Specifically, some of these substances are used to reduce filtration and cake thickness, to...

96

Dynamic filtration from emulsion mud. From Ferguson and Klotz.z Copyright 1954 by SPE-AIME.) Figure 6-16. Dynamic filtration from lime-starch mud. (From Ferguson and Klotz.24 Copyright 1954 by SPE-AIME.) Figure 6-16. Dynamic filtration from lime-starch mud. (From Ferguson and Klotz.24 Copyright 1954 by SPE-AIME.) Figure 6-17. Dependence of equilibrium dynamic filtration rate on mud flow velocity at 75 F. (From Ferguson and Kioto. Copyright 1954 by SPE-AIME.) Figure 6-17. Dependence...

725

The pressure differences shown in Table 9-7 show that calculating bottom-hole pressures in deep hot holes from the density of the mud at the surface can result in bottom-hole underpressures quite sufficient to cause a blowout. A computer program is available for predicting downhole mud temperatures from mud properties surface operating data and pipe, casing, and hole dimensions.5*- It is necessary to know the local geothermal gradient and the thermal properties of the downhole formations, at...

Rpm

Graphical interpretation of determination of flow parameters in a two speed direct indicating viscometer. As we iaw in Chapter 4, the clay particles present in drilling fluids are highly anisodimensional, and can build a structure at very low solid concentrations beca use of interaction between attractive and repulsive surface forces. At low shear rates the behavior of the clay particles is still influenced by these force*, and. in consequence, the viscosity is relatively high but,...

Equipment And Procedures For Evaluating Drilling Fluid Performance

Devising tests that will accurately describe how drilling fluids behave downhole is virtually an impossible task. Most drilling fluids are complex mixtures of interacting components, and their properties change markedly with changes in temperature, shear rate, and shear history. As they circulate through the borehole, drilling fluids are subjected to ever changing conditions turbulent flow in the drill pipe, intense shearing at the bit, and nominal laminar flow in the annulus at frequently...

Xanthan Gum XC Polymer

Xanthan gum is properly classed with the natural polymers, although it is actually obtained in its produced rather than in its natural form. Xanthan gum production method was developed at the Northern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Peoria, Illinois, in 1961. Jeanes et al129 present a recent review containing 49 references on xanthan. Xanthan is a water-soluble polysaccharide produced by bacterial action (genus Xanthomonas) on...

Drilling Fluid Selection

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...

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...

1963

Kelly, J., Jr., How Lignosulfonates Behave at High Temperatures, Oil Gas J (Oct. 5, 1964). pp. 112-119. 265. Skelly, W.G., and Dieball, D.E., Behavior of Chromate in Drilling Fluids Containing Chrome Lignosulfonate, Soc Petrol Eng. J. (June. 1970). pp. 140 144. 266. Skelly, W.G., and Kjellstrand, J.A., The Thermal Degradation of Modified Lignosulfonates in Drilling Mud, API Paper No. 926 11 C, API Div. Prod, meeting. Houston, March 4, 1966. 267. Bush, H.f ., Barbee, R., and Simpson, J.P.,...

7393

M.C., Fluid Release Mechanisms in Compacting Marine Mudrocks and Their Importance in Oil Exploration, AAPG Bull., vol. 51, No. 7 (July, 1967). pp. 1240-1254. 11. Perry, E.A., Jr., and Hower, J., Late-Stage Dehydration in Deeply Buried Peletic Sediments, AAPG Bull., vol. 56, No. 10 (Oct., 1972). pp. 2013-2021 12. Schmidt, G.W., Interstitial Water Composition and Geochemistry of Deep Gulf Coast Shales and Sandstones, APPG Bull., vol. 57, No. 2 (Feb., 1973). pp 321 337. 1.3....

2k 3k 4k 5k

The composite failure envelope showing a family of Mohr stress circles tangent at point A and one Mohr stress circle tangent at each of points B and C. (From Secor.4i Courtesy Am. J. Science.) Figure 9-35. A failure envelope diagram showing the effect of an incremental increase of fluid pressure on the position of the Mohr stress circle, assuming the total principal stresses remain constant. (From Secor.41 Courtesy Am. J. Science.) Figure 9-35. A failure envelope diagram showing...

Environmental Aspects of Drilling Fluids

Much attention has been given in recent years to the environmental aspects of both the drilling operation and the drilling fluid components. Well-deserved concern with the possibility of polluting under-ground water supplies and of damaging marine organisms, as well as with the more readily observed effects on soil productivity and surface water quality, has stimulated wide-spread studies on this subject. Extensive work is now in progress, and this brief survey may be of only historical...

Table 112 Barite Requirements for API Specification

Sieve (ASTM) no. 200 3.0 maximum Residue on U.S. Sieve (ASTM) no. 325 5.0 minimum Soluble alkaline earth metals as calcium 250 ppm, maximum Courtesy API Specification for Oil-Well Drilling-Fluid Materials, API Spec. 13-A, seventh edition. Mav. 1979. used about 750 lb bbl (2100 kg m3). The minimum concentration of barite might be as low as 10 lb bbl (28 kg m3), although usually it would be substantially higher. The quantity of barite required to raise the density of a given...

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...

Tct In Drilling

1 TCT thermodynamic crystallization temperature 1 TCT thermodynamic crystallization temperature Table 10-8 Sodium Chloride Sodium Bromide Brine Density H20 NaCl NaBr Freezing Point 10.0 .886 119.0 0 4-30 10.5 .871 89.6 46.4 19 11,5 .841 48.8 139.0 -12 12.0 .826 28.5 186.0 -3 TCT 12.5 .812 8.1 232.0 31 TCT 12.7 .806 0 251.0 45 TCT Based on 100 NaCl and 95 NaBr TCT thermodynamic crystallization temperature tion temperature is matched to environmental conditions. Density and crystallization...

Clay Mineralogy And The Colloid Chemistry Of Drilling Fluids

Anyone concerned with drilling fluids technology should have a good basic knowledge of clay mineralogy, as clay provides the colloidal base of nearly all aqueous muds, and is also used in oil-based drilling fluids. Drill cuttings from argillaceous formations become incorporated in the drilling fluid, and profoundly change its properties. The stability of the borehole depends to a large extent on interactions between the drilling fluid and exposed shale formations. Interactions between the mud...

Attapulgite Requirements for API Specification

Moisture, as shipped from point of manufacture Wet screen analysis, residue on U.S. Sieve ASTM no. 200 Properties of a suspension of 20 g attapulgite clay as received in 350 cmJ of a saturated sodium chloride solution stirred 20 minutes 2 drops of octyl alcohol added to break the foam. Courtes API Specification for OH- Well Drilling-Fluid Materials, API Spec. 13-A. seventh edition. May, 1979. and special methods of rapid drying while pulverizing are recommended as a method of further improving...

N

Pressure of fluid in formation pores pw pressure required to induce a fracture pm plus pressure drop in annulus, plus any transient pressure Overburden pressure, solids plus liquids . Mondshine, T.C., Drilling Mud Lubricity, Oil Gas J. Dec. 7. 1970 . pp. 70 77. 2. Rosenberg, M., and Tailleur, R.H., Increased Drill Bit Use Through Use ot Extreme Pressure Lubricant Drilling Fluids, J. Petrol. Technol. Aug., 1959 . pp 195-202 Trans AIME, vol. 216. 3. Browning, W.C., Extreme-Pressure Lubes in...

01

Solids Content of Drilling Mud Volume Percent Figure 2-9. Effect of solids on drilling performance. From World Oil. Further studies96 led to the introduction of a bentonite extender polymer for the preparation of a low-solids, fresh-water mud. This mud was composed of about 3 by weight of bentonite, 0.01 polymer and 0.05 soda ash. A five-well test program in Wood County, Texas, showed the effect of solids content on drilling progress, as illustrated in Figure 2-9.9 7 In a later report,98 the...

Pressure Control by Mud Density

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 OH. Figure 2-3. This mud mixer used shortly after the turn of the century served...

Rapid Growth of the Mud Industry

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 Oil 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...

Oil Emulsion Muds

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...