抗高温可膨胀水基堵漏剂的制备与性能评价

Preparation and Performance Evaluation of High Temperature Resistant Expandable Plugging Agent

高温裂缝性地层由于裂缝结构复杂、堵漏材料难以与裂缝开度精准匹配,常面临着封堵层承压能力不足而导致的重复井漏问题。针对高温裂缝地层面临的井漏技术难题,开展了抗高温可膨胀堵漏剂的研制和评价。基于橡胶颗粒具有的弹性变形特征,结合改性聚氨酯的吸水膨胀特性,研制了一种新型抗高温可膨胀堵漏剂。评价结果表明,该堵漏剂在90~150℃热滚条件下,质量膨胀量可达8~10倍,且主要膨胀时间在4~8 h。具有良好的配伍性能,在地层水及钻井液中长时间浸泡不影响其膨胀效果;具有较好的抗盐性能,与堵漏基浆相比,在20%NaCl和10%CaCl2污染条件下膨胀量降低率仅为8%和21.7%;具有较好的力学强度特性,(90~150℃)/12h热滚条件下,经过5 MPa抗压测试,D50粒度降级率小于20%。形成的封堵配方可封堵3 mm×2 mm裂缝,承压能力达6 MPa,可较好地满足高温裂缝性地层的堵漏需求。该抗高温堵漏剂同时兼顾的弹性膨胀和强度特性具有广阔的应用前景,为大港油田高温裂缝地层井漏问题的解决,提供了有效的技术方案。

Due to the complex fracture structure and the difficulty of accurately matching the plugging material with the fracture opening, the high-temperature fractured formation often faces the problem of repeated well lost circulation caused by the insufficient pressure bearing capacity of the plugging layer.Aiming at the technical problem of lost circulation in high-temperature fractured formation, the development and evaluation of high-temperature expandable plugging agent are carried out.Based on the elastic deformation characteristics of rubber particles, combined with the water absorption and expansion characteristics of modified polyurethane, a new high temperature resistant expandable plugging agent was developed. The evaluation results show that the mass expansion of the plugging agent can reach 8-10 times under the condition of hot rolling at 90-150 ℃,and the main expansion time is 4-8 h.It has good compatibility, and the expansion effect will not be affected even when soaking in formation water and drilling fluid for a long time.It has good salt resistance.Compared with the plugging base slurry, the expansion reduction rate is only 8% and 21.7% under the pollution of 20%NaCl and 10% CaCl2.It has good mechanical strength characteristics. Under the condition of 90-150 ℃/12 h hot rolling, after 5 MPa compressive test, the particle size degradation rate of D50 value is less than 20%.The formed plugging formula can block 3×2 mm fracture with pressure bearing capacity of 6 MPa, which can better meet the plugging requirements of high-temperature fractured formation.The high temperature resistant plugging agent with elastic expansion and strength characteristics have broad application prospects, providing an effective technical scheme for solving the problem of lost circulation in high temperature fracture formations in Dagang Oilfield.