Analyzing the wettability of tight sandstone of Taiyuan Formation in Shenfu block, eastern margin of Ordos Basin

Abstract

Abstract Reservoir wettability is an important indicator in the study of multiphase fluids in oil reservoirs. It involves the migration of crude oil from source rocks to reservoirs, accumulation in the reservoirs, and the entire process of crude oil development. The distribution characteristics of the wettability of sandstone reservoirs can provide a certain reference for the analysis of tight sandstone oil migration and accumulation mechanisms, and the exploration and development of tight sandstone reservoirs. This paper measures the contact angle between oil and tight sandstone by using the hanging drop method. Using the KRUSS DSA100S video optical contact angle measuring instrument, 25 unwashed oil tight cores and 62 washed oil tight cores are tested, respectively. Experimental analysis shows that the contact angle of the tight sandstones of the Taiyuan Formation in the Shenfu block of the Ordos Basin ranges from 50° to 150°, and the sample contact angles are concentrated between 70° to 110°. The wettability of the reservoir is mainly of the intermediate wet type, followed by the water wet type and the oil wet type.