1 Drilling, Completion and Workover Fluids 2008. Special Supplement to Published in June 2008. Copyright 2008 Gulf Publishing Co. All rights reserved. For additional copies, contact Gulf Publishing Company. Telephone: 713-529-4301 Fax: WORLD OIL, Gulf Publishing Co., Attention: Reprint Department, Fax No. 713-520-4433. Mailing Address: Gulf Publishing Co., Box 2608, Houston, TX 77252 USA. WORLD OIL'S. FLUIDS 2008. Classifications of fluid systems Descriptions of fluid-system classi- anhydrite contamination but are sus- sulate drill solids or to extend bentonite fications, product functions and source ceptible to gelation and solidification at clay in a low-solids mud. companies are listed on these pages. Sys- high temperatures. tem descriptions and product definitions Saltwater systems.
2 Several mud sys- have been kept as simple as possible and, High-performance water-based tems are included in this classification. wherever practical, they reflect general muds (HPWBM). These are usually re- Saturated salt systems are used to drill salt industry practice and terminology con- formulated polymer systems containing formations. Lower levels are usually re- sistent with descriptions adopted by the system-specific products to deliver shale ferred to as brackish or seawater systems. American Petroleum Institute (API) and stability, clay and cuttings inhibition, Saltwater muds are usually prepared the International Association of Drilling lubricity and high ROP, while minimiz- from brackish, seawater or produced- Contractors (IADC). ing bit balling/accretion and downhole water sources and dry sodium chloride torque problems.
3 Some HPWBM use (or other salts, such as potassium chlo- WATER-BASED SYSTEMS borehole stabilizing products to reduce ride used for shale inhibition), are added pore pressure transmission similar to to achieve desired salinity. Various spe- Non-dispersed. These systems include oil-based muds. Therefore, HPWBM cialty products, such as attapulgite, car- spud muds, natural muds and other are suitable to use whenever environ- boxymethyl cellulose (CMC), starch and lightly treated systems that are generally mental liabilities and associated waste others, are used to increase viscosity for used for shallow wells or top-hole drill- management costs limit the application hole-cleaning properties and to reduce ing. Thinners and dispersants are not of OBM/SBM. fluid loss.
4 Added to disperse drill solids and clay particles. Low solids. Listings include systems in OIL-BASED MUD SYSTEMS. which the amount (volume) and type of Oil-based systems are used in vari- Dispersed. At greater depths, where solids are controlled. Total solids should ous applications, where fluid stabil- higher densities are required, or where not range higher than about 6% to 10% ity and inhibition are necessary, such as hole conditions may be problematic, by volume. Clay solids should be some high-temperature wells, deep holes, and muds are often dispersed, typically with 3% or less and exhibit a ratio of drilled where sticking and hole stabilization are lignosulfonates, lignites or tannins. solids to bentonite of less than 2:1. problems. They consist of two types of These and similar products are effec- Low-solids systems typically use poly- systems: tive deflocculants and filtrate reducers.
5 Mer additive as a viscosifier or bentonite 1. Invert emulsion muds are water-in-oil Potassium-containing chemicals are extender and are non-dispersed. One emulsions, typically with calcium chloride frequently used to provide greater shale primary advantage of low-solids systems brine as the emulsified phase and oil as the inhibition. Specialized chemicals are is that they significantly improve drill- continuous phase. They may contain as also added to adjust or maintain specific ing penetration rate. much as 50% brine in the liquid phase. mud properties. Invert emulsion muds are a relaxed . Polymer/PA/PHPA. Muds incorporat- emulsion, and have lower electrical sta- Calcium treated. Divalent cations, ing generally long-chain, high-molec- bilities and higher fluid-loss values.
6 Con- such as calcium and magnesium, when ular-weight polymers are used to either centration of additives and brine content/. added to a freshwater drilling mud, in- encapsulate drill solids to prevent disper- salinity are varied to control rheological, hibit formation clay and shale swelling. sion and coat shales for inhibition, or for filtration and emulsion stability. High levels of soluble calcium are used to increasing viscosity and reducing fluid 2. Oil-based muds are formulated with control sloughing shale and hole enlarge- loss. Various polymers are available for only oil as the liquid phase and are often ment, and to prevent formation damage. these purposes, including cellulose, natu- used as coring fluids. Although these sys- Hydrated lime (calcium hydroxide), ral gum-based products, and acrylamide.
7 Tems pick up water from the formation, gypsum (calcium sulfate) and calcium Frequently, inhibiting salts, such as KCl no additional water or brine is added. chloride are principal ingredients of cal- or NaCl, are used to provide greater shale All oil systems require higher additional cium systems. stability in all of these fluids. These sys- gelling agents for viscosity. Specialized Calcium-treated muds resist salt and tems usually contain a minimum amount oil-based mud additives include: emulsi- of bentonite and may be sensitive to fiers and wetting agents (commonly fatty divalent cations, such as calcium and acids and amine derivatives) for viscos- magnesium. Most polymers have tem- ity; high-molecular-weight soaps; surfac- On The Cover: Completion fluids perature limits below 300 F but, under tants; amine-treated organic materials.
8 Technicians are consulting with a cli- certain conditions, may be used in hotter organo clays and lime for alkalinity. ent on a rig in the North Sea. Photo wells. A special class of water-based muds courtesy of MI-SWACO. use partially hydrolyzed polyacrylamide Completion FLUIDS. (PHPA) as an additive, either to encap- Solids-free and typically formulat- World Oil JUNE 2008 F 105. WORLD OIL'S FLUIDS 2008. Abbreviations of company names ADM Archer Daniels, Midland, Decatur, IL, USA, Croda Croda (form. Uniqema Inc.), New Castle, M&D M&D Industries of Louisiana, Lafayette, DE, USA, LA, USA, AHC Advance Hydrocarbon Corp., DSC DSC Incorporated, The Woodlands, TX, MASI Masi Technologies, LLC, Lafayette, LA, College Station, TX, USA USA, USA AMBAR Ambar Lone Star Fluid Services, DX Oilfield DX Oilfield Products, Inc.
9 , Dixie Mayco Mayco-Wellchem, Inc., Houston, TX, Lafayette, LA, USA, Chemical Co., Houston, TX, USA, USA, AVA Ava Drilling Fluids, , Rome, Italy, Deep South Deep South Chemical, Inc., Messina Messina, Inc., Dallas, TX, USA, Lafayette, LA, USA, Akzo Akzo Nobel, Amersfoort, The Netherlands, Montello Montello, Inc., Tulsa, OK, USA, Alliance Alliance Drilling Fluids, LLC, Midland, Densimix Densimix Inc., Houston, TX, USA, TX, USA, NER NER, , Houston, TX, USA, Alpine Alpine Specialty Chemicals, Houston, TX, Dow The Dow Chemical Co., Midland, MI, USA, USA, Nalco Nalco Company Energy Chemicals, Am. Gil. American Gilsonite Co., Houston, TX, Drill. Spec. Drilling Specialties, The Sugar Land, TX, USA, USA, Woodlands, TX, USA, Newpark Newpark Drilling Fluids, Houston, TX, Anchor Anchor Drilling Fluids, Tulsa, OK, USA, USA, Drillchem Drillchem Drilling Solutions, Lafayette, LA, USA, OLEON Oleon, Oelegem, Belgium, Aqua-Clear Aqua-Clear, Inc.
10 , Charleston, WV, Drillsafe DrillSafe Janel Int., Ustron, Poland, USA, Pacer Pacer Corporation, Custer, SD, USA, Aqualon Aqualon Oil and Gas Technologies, div. Drill Tech Drill Tech Environmental Services, of Hercules, Inc., The Woodlands, TX, USA, Inc., Schriever, LA, USA Progress Progress Chemical Sales Co., Drilpro Drilpro Fluids Ltd., Houston, TX, USA Houston, TX, USA. Aquaness Aquaness Chemical Division, div. of Baker Petrolite, Sugar Land, TX, USA, EMEC EMEC Calkem UK Ltd., Kent, UK. Pure Fluids Pure Fluids Ecofluids Ecofluids, Inc., Houston, TX, USA, (previously World Fluids plc), Norfolk, UK. BARZAGHI BARZAGHI srl, Arluno, Italy, Rapid Rapid Drilling Fluids, Lafayette, LA, USA, Elementis Elementis Specialities, Hightstown, NJ, USA, BASF BASF Construction Polymers GmbH (form.)