Single Well Alkaline-Surfactant Injectivity Improvement Test in the Big Sinking Field

Abstract

TX 75083-3836, U.S.A., fax 01-972-952-9435. AbstractThe Big Sinking Field is a mature waterflood in the Appalachian Basin of Eastern Kentucky. The 100 plus million barrel (15.9 million m 3 ) field is primarily a shallow tight oil reservoir at 1,150 feet (350 m). A primary constraint to production is the ability to inject fluid into the reservoir. This project was an effort to increase injectivity by injecting an alkali-surfactant solution to reduce the residual oil saturation with a resultant increase in effective permeability to water. Oil is mobilized away from the injection well bore where a substantial portion of the injection pressure is lost by reducing capillary forces that trap oil. A new well was drilled and cored, and a laboratory program performed prior to field implementation. A variety of mixtures of alkali and surfactant reduced the interfacial tension between oil and water to 0.001 dyne/cm from 23.6 dyne/cm. Injection of a Na 2 CO 3 plus ORS-62HF alkaline-surfactant solution increased the relative water permeability by 425% and a NaOH plus AX-210-6 alkaline-surfactant solution increased the effective water permeability by 310%. Subsequent fresh water injection resulted in a loss of effective permeability to water to 155% times the original waterflood base for the Na 2 CO 3 plus ORS-62HF solution. The NaOH plus AX-210-6 coreflood maintained injectivity at 325% with subsequent water injection. In September 2003, injectivity testing began with injection of fresh water into a newly completed well to establish initial injection rate. A 1,500 barrel (238 m 3 ) injection of NaOH plus ORS-162HF alkaline-surfactant solution followed. Return of fresh water injection showed an increase in fresh water injection from 41 to 75 barrels per day (6.5 to 11.9 m 3 ).

Coupling the Alkaline-Surfactant-Polymer Technology and the Gelation Technology to Maximize Oil Production

“…It's characteristics have been described elsewhere. 1 Polymers used in the linear corefloods are listed in Table 1. Chemicals were dissolved in 1.0 wt% sodium chloride.…”

Unraveling the Impact of Ethylenediaminetetraacetic Acid Chelating Agents on the Oil Recovery Processes: An Insight into Its Role in Fluid–Fluid and Rock–Fluid Interactions

“…Tertiary methods, specifically recognized as enhanced oil recovery (EOR) techniques, come into play in this stage. EOR techniques contribute to a comprehensive enhancement in the effectiveness of oil displacement, considering both microscopic and macroscopic parameters. , EOR methods frequently employ polymers, surfactants, and alkalis, − chosen for their widespread application in modifying the characteristics of both rock surfaces and reservoir fluids. Chemical enhanced oil recovery (CEOR) methods boost oil recovery by enhancing the efficiency of injected water in displacing oil within the reservoir.…”