致密油藏长段水平井防漏堵漏技术

Leakage Prevention and Plugging Technology of Long Section Horizontal Well in Tight Oil Reserviors

王广财 雍富华 朱夫立 王品德 刘禧元 张振宇 许 军

WANG Guangcai，YONG Fuhua，ZHU Fuli，WANG Pinde，LIU Xiyuan，ZHANG Zhenyu，XU Jun

吐哈盆地三塘湖油田西峡沟构造带二叠系条湖组地层为裂缝性油藏，钻井开发过程中恶性井漏频繁发生。为了解决三塘湖油田马 49区块致密油藏的恶性井漏难题，在分析马 49区块已钻井的井漏原因的基础上，开发了一种凝胶复合防漏堵漏技术，研究了凝胶复合防漏堵漏体系对水平井的配伍性、可泵性、抗温性和承压能力，并报道了该体系的现场应用效果。研究表明，所配制的凝胶复合防漏堵漏体系与水平井的配伍性良好；该体系的成胶时间为 30 min，可泵性良好；该体系具有较强的抗温性能，在 100℃老化不同时间后的凝胶复合防漏堵漏浆侵入砂床的深度变化不大；该体系具有良好的封堵承压能力，在静态/动态情况下均可在宽度为 1～ 3 mm缝隙中形成有效封堵层。凝胶复合防漏堵漏技术成功解决了马 49区块致密油藏恶性漏失难题，比同区块平均漏失量减低 94.57%，堵漏损失时间节约 89.51%，钻井周期节约 37.26%，实现了钻井提速提效的目的。图 1表4参12

The Xixiagou tectonic belt Dyas lake group formation in Santanghu oilfield located in Tuha Basin is fractured reservoir.Serious well leakage frequently took place during the drilling development. In order to solve the problem of serious well leakage in Santanghu oilfield Ma-49 block tight reservoir，the composite gel drilling fluid（CGDF）technique was developed based on the analysis of the reasons of well leakage regulation in Ma-49 block. The compatibility，pumpability，high-temperature resistance and bearing capacity of the CGDF was analyzed，and the effect of the field application was mentioned. The research showed that the compatibility between the CGDF and the reservior was of high performance. The gelling time of the CGDF was 30 min，which indicated that the CGDF had good pumpability. There was not obvious change of CGDF mud invading depth in the casting bed after aged at the temperature of 100℃ for different aging time，so the CGDF system was of high temperature resistance. Moreover，The CGDF was of good pressure resisting and plugging capability，which could form the effective plugging formation in the gap of 1—3 mm in static/dynamic state condition. The CGDF technique solved the serious well leakage in Ma-49 block tight reservoir and optimized the effects of the drilling process. By applying the CGDF technique，94.57% of the average leakage in the same block was reduced，89.51% of the plugging time was shorted，and 37.26% of the drilling cycle was saved.