Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 2/8/2003
Publication Date: 6/5/2003
Citation: Sifferman, T.R., Muijs, H.M., Fanta, G.F., Felker, F.C., Erhan,, S.M. 2003. STARCH-LUBRICANT COMPOSITIONS FOR IMPROVED LUBRICITY AND FLUID LOSS IN WATER-BASED DRILLING MUDS. Meeting Abstract. xx.
Technical Abstract: The development of water-based mud systems that approach the performance of oil-based muds in lubricity, rate of penetration and borehole stability is an ongoing effort. The use of starch-lubricant compositions as environmentally safe, non-toxic, stable dispersions in water-based drilling muds was studied. Starch-lubricant compositions were prepared from various commercial olefins, esters and also from proprietary compounds by jet-cooking mixtures of water, starch, and lubricant to produce aqueous starch dispersions containing suspended lubricant droplets 1-10 microns in diameter. These droplets do not separate or coalesce, and dispersions can also be drum dried and reduced to dry, non-oily powders containing 28% lubricant by weight. Dry powders were added (at 5.0 lb/barrel) to laboratory-prepared lignosulfonate drilling mud (generic #7). Standard laboratory tests indicated that starch-lubricant compositions lowered both API and HTHP fluid loss values. More importantly, coefficient of friction values were 12-46% of the untreated base mud, and were similar to those of oil-based muds. Muds formulated with starch-lubricant compositions contained only 0.5% lubricant (v/v), yet performed better than a typical field mud control containing 3% lubricant (v/v). These exceptionally good results with one-sixth the amount of a typical lubricant suggest that the size and distribution of lubricant droplets achieved in these systems may enhance lubricant efficiency. CONCLUSIONS 1. A new family of dry, starch-based lubricants can be blended easily into water-based drilling muds to provide coefficient of friction values similar to those observed with oil-based muds. 2. Muds prepared with these starch-based lubricants also have good fluid loss properties. 3. Starch is inexpensive and environmentally safe, and its presence at the lubricant-water interface serves as the dispersant for the water-immiscible lubricant. No emulsifiers are used in the preparation of these materials. 4. Powdered products can be transported to the drilling site (especially offshore), providing considerable cost savings and ease in transport.