连续油管拖动均匀酸化分支水平井

Uniformly acidized lateral horizontal well with drawing coiled tubing

针对深层碳酸盐岩油气藏埋藏深、非均质性强、钻井周期长和成本高等特点,为进一步发挥水平井"少井高产"的优势,扩大单井控制面积,提高储层动用程度以及增加单井产量,在哈萨克斯坦K油田开展一口4级完井的分支水平井现场试验.通过室内实验确定了清洁自转向酸液配方,并对其暂堵转向、缓速和低伤害等性能进行室内测试.两分支都采用"直-增-稳"3段制井身剖面和筛管完井方式,并在完井后对侧分支进行了氮气泡沫暂堵转向酸化,主分支采用连续油管拖动水力喷射酸化技术解堵,措施实施后两分支合采投产.根据该油田储层、岩性和物性等特征,对施工压力、排量和连续油管拖动速度参数进行了优化,并计算了酸化后的表皮系数.结果显示,两个分支都达到了酸化解堵和恢复产能的目的,说明双分支水平井酸化工艺在该油田取得了较好的应用效果,具有广阔的应用前景.

As for deeply buried and heterogeneous carbonate reservoirs,which require long well-drilling periods with high cost,we carried a pilot test for lateral horizontal well with 4th-level well completion in Kazakhstan K oilfield in order to increase the well-controlled area and production rate of horizontal wells. Meanwhile,the process also aimed to enhance the degree of formation development and take full advantage of the idea of ＂ fewer wells and higher production＂. Firstly,according to in-room laboratory test results,a clean self-diverting acid system was determined.The performance of the self-diverting acid in temporary blocking,retarding and low damage was tested. In practice,well trajectories of the two laterals were drilled in the pattern of three sections： vertical,angle increasing,and deviated. After the completion of the well,the secondary lateral was acidized by the diverting acid mixed with nitrogen,and the primary lateral was treated by drawing back coiled tubing. Subsequently,the two laterals went into operation at the same time. We optimize the treating pressure,the pumping rate,and coiled tubing drawing back velocity based on the formation,rock properties and physical properties of this oilfield. We calculate the skin factor after acidization. Results indicate that both of these two branches are acidized successfully thus restoring the productivity significantly,which implies broad application prospects of the lateral horizontal well drilling with acidizing technology in the oilfield.