Volume 27: Closing Carbon Cycles – A Transformation Process Involving Technology, Economy, and Society: Part II

Degassing Process and Water-flooding Oil and Gas Mechanism of Cores with Different Fracture Occurrences in Weakly Volatile Carbonate Reservoirs Hongxin Guo, Linsong Cheng, Pin Jia, Peng Wang

Abstract

The weakly volatile crude oil in the carbonate reservoir is easily degassed when the pressure is reduced. In this paper, weakly volatile oil with similar dissolved gas-oil ratio to actual oil field was prepared, and three fracture occurrences carbonate cores were designed. The self-designed oil-gas-water three-phase metering device was used to accurately measure the flow. The research results showed that GOR presented three stages: rising stage, falling stage and steady rising stage. For the GOR of low-angle through fracture core, the peak value is the highest during water injection. In studies of different depletion degrees, an appropriate degree of degassing not only effectively utilizes the elastic energy of the gas, but also reduces the development cost of the oil field.

Keywords weakly volatile oil reservoirs, fracture occurrence, degassing process, oil-gas-water three-phase fluid flow