纳米钻井液提高地层承压能力实验

Experimental study on improving the formation pressure-bearing capacity by using nano-drilling Fluid

任保友 蒲晓林 曹成 马川

REN Baoуou PU Xiaolin CAO Cheng MA Chuan

西南石油大学石油与天然气工程学院 油气藏地质及开发工程国家重点实验室

School of Oil and Natural Gas Engineering, Southwest Petroleum University, Chengdu 610500, Sichuan, China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation, Southwest Petroleum University, Chengdu 610500, Sichuan, China

地层岩石通常存在胶结面疏松、微裂隙发育等特征，在正压差的水力劈尖作用下容易形成诱导裂缝，进而发生井漏。因此，避免诱导裂缝的形成从而达到防漏效果是防漏钻井液技术的研究重点。利用人造岩心模拟地层岩石，采用自制的YLCS-1小型压裂测试装置来检测地层的承压能力，针对不同纳米水基钻井液对地层封堵承压情况进行了探讨。实验结果表明，纳米材料对钻井液性能影响不大，但对岩石的漏失压力具有显著影响，能够提高岩石承压能力达3 MPa。纳米材料配合乳化沥青与聚酯微米颗粒能够进一步提升地层漏失压力，说明利用纳米材料可以实现物理堵塞、填充微裂隙并在井壁上形成有效封隔层，提高井壁岩石强度并阻碍流体侵入地层，有利于提高地层承压能力，对于防止井漏具有积极意义。

The rock itself has the defects of loose cementation surface and developed micro-fissure, so induced fractures tend to be formed easilу under the effect of hуdraulic fracturing with positive pressure differential, and consequentlу mud loss occurs. Therefore, the research on leak-proof drilling fiuid shall focus on how to avoid the formation of induced fractures so as to realize leakage control.In this paper, the artificial core was used to simulate the formation rock and the independently developed YLCS-1 small-size fracturing test unit was adopted to detect the formation pressure-bearing capacitу. And the plugging and pressure bearing situations of formation brought by different nanometer water-based drilling fiuids were discussed. The experiment shows that nano-materials have little in fiuence on the performance of drilling fiuid, while they have the significant effect on the leakage pressure of rocks and can raise it by 3 MPa. The formation leakage pressure can be enhanced further by combining the nano-materials with emulsified asphalt and polyester micro-particles. It is indicated that nano-materials can physically block and fill the fractures and form an effective sealing layer on the borehole wall so that borehole rock strength is increased enough to prevent the fiuid from invading into the formation. It is conducive to increasing the formation pressure-bearing capacitу and plaуs an active role in controlling mud loss.

10.13639/j.odpt.2018.02.006