超深碳酸盐岩油藏水平井套管分段酸压技术实践

PRACTICE OF STAGE ACID FRAC IN CASED HORIZONTAL WELL IN ULTRADEEP CARBONATE RESERVOIR

酸压是碳酸盐岩储层增产的有效措施,对于塔里木哈拉哈塘区块超深碳酸盐岩水平井,如何兼顾水平井段的充分改造和后期修井作业,是亟待解决的技术难题。HA6H井油藏中深6 590 m,水平段长498 m,在该区块首次采用"套管封隔器+可钻式压裂滑套"分段工具和段内暂堵转向技术,分段设计依据井筒与优势储层位置的距离来设定缝高,再结合间距比和流动阻力的关系来优化段数和裂缝间距,以降低裂缝间压力干扰的影响,经优化设计该井分10段酸压改造,酸压后采用4 mm油嘴掺稀求产,油压22.65 MPa,日产油77.9 m^3,日产气11 792 m^3,截止目前累计产油11 176 t,取得很好的分段酸压效果。

Acid fracturing is an effective measure for carbonate reservoir stimulation. How to balance the stimulation and the later workover operation along the horizontal interval is a technical problem to be solved for horizontal wells in deep carbonates at Halaha Pond block,Tarim. Well HA6 H was 6850 m deep,drilled into the reservoir. The horizontal section was 498 m long. Combining use of casing packer,staging tool of drillable sliding sleeve for fracturing,and temporary plugging & diverting technology in the stages,was first used at this block. The fracture height was designed according to the distance between the borehole and the dominant payzone. And the number of stages and the space between the fractures were optimized based on the relationship between the spacing ratio and the flow resistance,in order to reduce the effects of pressure interference between fractures. This well was designed with 10- stage acid frac,? 4mm choke used for production. The tubing pressure reached 22. 65 MPa,oil rate 77.9 m^3 per day,gas rate 11792 m^3 per day. This acid frac was proven effective for stimulation.