Submitted to: Oilfield Chemicals Symposium
Publication Type: Proceedings
Publication Acceptance Date: 12/15/2002
Publication Date: 2/8/2003
Citation: Sifferman, T.R., Muijs, H.M., Fanta, G.F., Felker, F.C., Erhan, S.M. 2003. STARCH-LUBRICANT COMPOSITION FOR IMPROVED LUBRICITY AND FLUID LOSS IN WATER-BASED DRILLING MUDS. Oilfield Chemicals Symposium. xx. Interpretive Summary: When mixtures of water, starch, and oil are treated with high pressure steam, using a processing technique known as steam jet cooking; new products having commercially useful properties are obtained. These products have been given the trademark Fantesk**TM by the USDA. Fantesk**TM products contain microscopic droplets of oil suspended in a water dispersion of starch, and these droplets do not separate or coalesce, even when dispersions are dried. We have found that various water - immiscible lubricants can be incorporated into Fantesk**TM compositions to yield new starch-based lubricant systems for addition to oil drilling fluids. These new lubricant systems can increase the lubricity of drilling fluids by over 46% and can also reduce drilling fluid loss into the drilled rock formations. Moreover, Fantesk**TM products are environmentally friendly, since they eliminate the need for potentially toxic emulsifiers and dispersants in drilling mud formulations.
Technical Abstract: Water-based mud systems that approach the performance of oil-based muds are an ongoing effort. Starch-lubricant compositons were developed as environmentally safe, non-toxic, stable dispersions in water-based drilling muds. Starch-lubricant compositions were prepared 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. The dispersions were drum dried and milled to dry, non-oily powders containing 28% lubricant by weight. These dry powders were then tested at 5 lb/barrel in laboratory-prepared lignosulfonate drilling muds. Various commercial olefins, esters, and/or polybutenes were evaluated as lubricants. Standard laboratory tests indicated that starch-lubricant compositions lowered both API and HTHP fluid loss values. More importantly, coefficient of friction values were 12-25% of the untreated base mud and were similar to the average values for oil-based muds. Muds formulated with starch-lubricant compositions usually 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. Therefore, further investigation of such formulations is warranted, including a field test to evaluate the advantages of this newly-patented technology.