屏蔽暂堵型储层保护钻开液在曹妃甸的应用

Application of Shielding Temporary-bridge Reservoir Protection Drilling Fluid in CFD Oilfield

曹妃甸11-2油田主力油层主要位于上第三系地层的馆陶组,储层段钻开液使用无固相免破胶的EZFLOW体系。馆陶组储层泥质胶结,疏松灰质含量重;钻遇灰质泥岩时钻速缓慢,钻屑研磨较细,影响了EZFLOW体系封堵性能。该体系的核心指标是PF-EZCARB颗粒级配,形成屏蔽暂堵保护储层,但是钻遇泥岩后,固相没有及时清除,影响了体系封堵性能,导致地层污染。曹妃甸项目组针对储层段泥岩或者泥质含量较高的井,从提高EZFLOW体系抑制性和封堵能力入手,体系补充加入3%,PF-JLX C、3%,~5%,的KCl,保证体系的抑制性能,控制较低的固相含量,不影响体系的封堵性能,从而维持较低的返排压力,在CFD11-2-A16H2井应用达到了预期效果,该井投产时产能达到配产要求。

Main oil reservoirs of CFD11-2 oilfield are mainly located in the Guantao formation of the Upper Tertiary strata, and the EZFLOW system with no solid-free and free gel is used in the drilling section. Mudstone of the Guantao group reservoir is cementing, loose gray matter content is bigger; the drilling speed is slow when drilling mudstone and the drilling cuttings are fine, affecting the blocking performance of EZFLOW. The core of the system is the PF-EZCARB particle gradation to form a temporary shielding storage protection reservoir. However, when drilling mudstone, the solid phase cannot be removed in time, which affects system blocking performance and leads to the formation pollution. For the reser- voir mud or muddy high content of wells, CFD project group focuses on the improvement of inhibitory performance and locking capacity of the EZFLOW system to ensure the suppression of the system performance by adding 3% PF-JLX C and 3-5% KCl. As a result, the inhibitory performance is guaranteed and lower solid content is realized, thus maintaining a low return pressure in the CFD11-2-A16H2 well application. The well has met the requirements on production capacity.