提高浅薄层稠油高周期吞吐效果方法研究

Study on high-periodic steam soak technique of heavy oil in thin-bedded layers

河南油田稠油油藏埋藏深度90-1 100 m,单层厚度1-4 m,层系组合厚度3-10 m,油层温度下脱气原油粘度90-160 000 mPa·s,具有“浅、薄、稠、散”特点。经过近二十年的稠油开采技术攻关,逐步形成了浅薄层稠油高周期吞吐配套开采技术,成功地将大于3 m的薄层稠油投入工业性开发,原油粘度界限增大到80 000 mPa·s,拓宽了稠油注蒸汽开采领域,使井楼、古城油田基本实现蒸汽吞吐综合不递减,吞吐采收率进一步提高到30．7％,油汽比达0．4,采油成本降低23％-30％,取得了较好的开发效果。

The heavy oil reservoirs of Henan Oilfield are characterized by shallow, thin, viscous and dispersive, with formation depth of 90 - 1 100 m, layer thickness of 1 - 4m, series combined thickness of 310 m and viscosity of gas ?free crude oil of 90-160 000 mPa·s. Through 20 years study on production techniques of heavy oil, high- periodic steam soak technique in thin - bedded layers has been established, which successfully makes heavy oil productive when the thickness of layers is over 3m, and viscosity limit is increased to 80 000 mPa·s. With this technique, development efficiency is greatly enhanced, for example, the recovery ratio of steam soak is up to 30. 7%, gas - oil ratio is 0. 4, and the production cost is decreased 23% -30%.