Potassium hydroxide for shale stability
Use of potassium hydroxide (KOH) in lime mud treated with modified starch deflocculant provides excellent shale stability in either weighted or unweighted muds. The added benefits are achieved with little difference in mud cost per barrel when compared to conventional lime muds. Also, the muds have reduced hole enlargement, cuttings dispersion and mud costs in comparison to lignosulfonate and KCl/ polymer muds. No problems with gelation have occurred in any of the wells drilled to date, and muds have remained stable at bottomhole temperatures to 300/sup 0/F. Lignosulfonate dispersants are not recommended and have not been required in any of the wells drilled with this system. Commonly available treating agents, except for the modified starch deflocculant, are used for routine system maintenance. The unique interaction of lime and potassium in these systems is partially responsible for their ability to control wellbore instability caused by shale hydration. Elimination of strong dispersants also has aided in combating hole erosion. Keys to successful use of the KLM system have been proper planning of the mud program, preparation of the rig, careful rig-site monitoring and maintenance of mud composition and properties. Rig-site pilot testing was done to prepare for changing drilling conditions. Overall, it has been found that lime muds treated with KOH and modified starch deflocculant combine many features considered desirable in today's complex drilling environments, and the combination of old and new technology has proven to be a cost-effective alternative to other popular mud systems.
- Research Organization:
- O'Brien-Goins-Simpson and Associates, Inc., Houston
- OSTI ID:
- 5171217
- Journal Information:
- World Oil; (United States), Vol. 197:6
- Country of Publication:
- United States
- Language:
- English
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03 NATURAL GAS
DRILLING FLUIDS
ADDITIVES
WELLS
COST BENEFIT ANALYSIS
FIELD TESTS
OPTIMIZATION
POTASSIUM HYDROXIDES
RESERVOIR ROCK
SHALES
STARCH
STRATA CONTROL
TECHNOLOGY UTILIZATION
WELL DRILLING
ALKALI METAL COMPOUNDS
CARBOHYDRATES
DRILLING
FLUIDS
HYDROGEN COMPOUNDS
HYDROXIDES
ORGANIC COMPOUNDS
OXYGEN COMPOUNDS
POLYSACCHARIDES
POTASSIUM COMPOUNDS
REAGENTS
ROCKS
SACCHARIDES
SEDIMENTARY ROCKS
TESTING
020300* - Petroleum- Drilling & Production
030300 - Natural Gas- Drilling
Production
& Processing