Abstract:

Taking the low production and efficiency wells in Bohai unconsolidated reservoir for example, this paper analyzed the perforation methods, set up an optimal empirical formulas for the half-fracture length and conductivity of supported fractures in 50 ~ 1000mD mid-high permeability reservoirs. Combined with the characteristics of offshore fracturing operation and seawater with high salinity and high calcium and magnesium ions, the seawater based fracturing fluid system was formed. In terms of proppant optimization, the optimization method of proppant particle size considering the critical flow rate of proppant fracture sand control was studied, and the consolidation strength of consolidated proppant was evaluated at different temperatures ranging from 50℃ to 180℃. According to the performed through-screen fracturing operations of eleven wells, the effect of increasing fluid and oil after fracturing in 9 wells was very significant. Practice has proved that through-screen fracturing technology can effectively solve the problem of low production and low efficiency in offshore high permeability loose sandstone reservoirs, which has a certain promotion value, but long-term effective sand control is the key to through-screen fracturing. 

Key words:

offshore oilfield；fracturing；screen completion；reservoir reconstruction；mid-high , permeability reservoir

摘要：

针对渤海油田中高渗疏松砂岩储层低产、低效井，分析了过筛管压裂射孔方式，建立了50～1000 mD中高渗储层压裂支撑裂缝半缝长和支撑裂缝导流能力优化经验公式。结合海上压裂作业及海水的高矿化度、高钙镁离子等特点，形成了海水基压裂液体系。支撑剂优选方面，研究了考虑支撑裂缝防砂临界流速的支撑剂粒径优选方法，同时评价了固结支撑剂在50～180℃不同温度下的固结强度。根据已实施11口井的过筛管压裂作业，9口井压裂之后增液、增油效果十分显著。实践证明过筛管压裂工艺可有效解决海上中高渗疏松砂岩储层低产、低效的难题，具有一定推广价值，但长期有效防砂是过筛管压裂工艺的关键。

关键词:

海上油田, 压裂, 筛管完井, 储层改造, 中高渗储层