Fracture Self-Adjusting High Temperature and High Pressure Plugging Simulation Device and Evaluation Method

在钻进过程中，由于井筒压力和地层压力的不断变化，当地层存在裂缝并发生漏失时，裂缝宽度便会发生动态变化，目前室内实验所采用的固定缝宽堵漏装置难以模拟裂缝蠕变情况且温压上限较低，导致堵漏配方在高温高压地层中的应用情况较差。为此，研制了一套裂缝自调节高温高压堵漏模拟装置，适用于所有桥接堵漏材料，可模拟裂缝在液柱压力和地层压力的共同作用下的蠕变情况，评价堵漏剂在地层高温高压环境下的动态封堵裂缝效果，通过测压点监测封堵架桥位置，完成了裂缝堵漏模拟评价方法可行性分析。结果表明：裂缝自调节高温高压堵漏模拟装置可有效评价裂缝宽度0.1~10 mm、温度232℃、压力25 MPa条件下的地层漏失情况与动态封堵裂缝效果，有效提升高温高压地层堵漏配方选择的准确性。In the process of drilling, due to the constant change of wellbore pressure and formation pressure, when fractures in the formation and leakage occurs, the fracture width will change dynamically. At present, the fixed fracture width plugging device used in laboratory experiments is difficult to simulate the creep of fractures and the upper limit of temperature and pressure is low, which leads to the poor application of the plugging formula in high temperature and high pressure formation. Therefore, a set of fracture self-regulating high temperature and high pressure plugging simulation device was developed, which can applicable to all bridging plugging material, simulate the creep of fracture under the combined action of liquid column pressure and formation pressure, evaluate the dynamic plugging effect of plugging agent in high temperature and high pressure environment, monitor the position of plugging bridge by pressure measuring point, and complete the feasibility analysis of fracture plugging simulation evaluation method. The results show that the fracture self-adjusting high temperature and high pressure plugging simulation device can effectively evaluate the formation leakage and dynamic plugging fracture effect under the conditions of fracture width 0.1~10 mm, temperature 232˚C and pressure 25 MPa, and effectively improve the accuracy of plugging formula selection in high temperature and high pressure formation.