针对在用油基钻井液钻进页岩气井水平段时井漏事故常有发生,造成严重的经济损失,研制了一种A型堵漏材料,对其进行了粒径分析,优选了最佳粒径范围,并在油基钻井液中评价了其堵漏性能.实验结果显示,A型堵漏剂的配伍性好,分散性好,吸油膨胀率高,抗150℃高温,砂床渗透侵入深度为1.0 cm,几乎是零滤失;与同类产品进行了对比,堵漏性能优于其他同类产品,具有好的防渗堵漏和裂缝堵漏效果;正向驱替压力为13 MPa,反向突破压力为1.2 MPa,承压强度高,反向驱替压力低,能够解决油基钻井液的渗透性漏失问题;A型堵漏剂与其他堵漏材料复配时能够有效解决1~3 mm裂缝漏失问题.形成了一套油基钻井液随钻堵漏技术,并在焦页195-1HF井进行现场应用,取得了良好的应用效果,不仅降低了焦页195-1HF井的钻井成本,同时缩短了钻井周期.%Oil base drilling fluids are generally the first choice in shale drilling because of their advantages such as low friction and weak shale swelling. Coexisting with the advantages of the oil base drilling fluids are their disadvantages, such as high drilling cost, especially when mud losses are happening, which always cause serious economic loss. To control losses of oil base drilling fluids into formations, a type A lost circulation material (LCM) has been developed, and its particle sizes analyzed. Experiments have been conducted to optimize the particle sizes for the effective and efficient control of oil base mud losses at different loss rates. The experimental results showed that the type A LCM has good compatibility with the drilling fluid used, good dispersity and high oil absorption rate. The type A LCM is resistant to high temperatures to 150 ℃, and penetrates into a sand bed for 1.0 cm with almost zero filtration. This LCM performs better than the same types of other LCMs in controlling seepage loss and mud losses into fractures. In flow experiments, the forward displacing pressure was 13 MPa, and the reverse breakthrough pressure was 1.2 MPa, indicating that the loss zones deposited with the type A LCM had high pressure bearing capacity and the deposited LCM was easy to remove. Composite LCM formulated with the type A LCM and other LCMs can resolve mud losses into fractures of 1-3 mm in size effectively. The mud loss control technology has been successfully used on the well Jiaoye195-1HF, reducing the drilling cost and the time required for drilling.
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