卫城低渗油藏高压注水井多氢酸酸化技术研究

卫城低渗油藏以卫城油田沙三中—沙四段油藏为主,油层埋深为2700~3500 m,动用地质储量3184×104 t,主要包括卫81、卫360块等6个开发单元。该类油藏埋藏深、储层低渗透,层间非均质性强,存在着局部注采井网不完善,区块注水压力高,高压欠注严重等问题,严重影响了油田开发水平的提高。在传统的酸液体系酸化过程中,一直没能较好的解决处理半径有限、易生成二次沉淀、残酸返排不彻底等问题。多氢酸的出现较好的解决了这些问题。自2012年1月至今,卫城低渗油藏现场应用11井次,成功率100%,平均单井日增注19 m3,降压8.0 Mpa,平均年有效期152天,平均年增注3137 m3。

Multiple Hydrogen Acidification Technology Research of Weicheng Low Permeability Reservoir High Pressure Water Injection Wells

Weicheng low permeability reservoir mainly contains sand3-sand4 reservoir, the depth ofoil layer is 2700-3500 m. Producing reserves is 3184x 104 t, including wei81,wei360 pieces of 6 developing units. The reservoir buried depth, the permeability is low, the difference among zones is graver. It contains problems such as local flooding pattern incomplete, high block flooding pressure, high-pressure owe injection, affected the level of oil field development greatly. In the acidification process of traditional acid system, have not been able to solve the problems, such as, process radius limited, easily produce secondary precipitate, can＇t completely flowback reacted acid. The emergence of hydrogen acid bitterly solve the problem. Since January 2012, weicheng oil field totally use hydrogen acid 11 wells, success rate 100 %,the injection of average single well increasing 19 m3, the pressure dropping 810 Mpa, average term of year validity is 152 days, average injection of year increasing 3137 m3.