高温高压裂缝性碳酸盐岩气藏封缝堵气技术

Sealing Technology to Control Gas Cut for Fractured Carbonate Gas Reservoirs at High Temperature and High Pressure

塔里木盆地塔中北坡奥陶系地层是典型的高温高压气层,气藏钻井工程中常诱发气侵溢流等复杂危害,严重影响了钻井的进度和安全。当前采取的封缝堵气措施面临着超高温高温高压及地层非均质性带来的压力窗口窄、钻井液性能不稳定、封堵材料效果不显著等诸多问题,很难快速高效地一次性形成稳固封堵区。以顺南区块为例,分析地质特征及带来的封缝堵气技术难点,考虑高温高压特征对现场井浆的影响,利用人工造缝岩心及封缝堵气实验装置开展室内评价实验。室内形成高强度复合架桥材料及广谱粒径纤维材料,优选纳米材料,并结合现场井浆对封缝堵气材料体系开展性能评价,体系与钻井液配伍性良好,能够有效封堵气层,储层伤害恢复程度大于90%。

The Ordovician system in the north slope of the Tarim Basin are typical high temperature and high pressure gas reservoirs, and gas invasion and overflow often occur in the gas reservoir drilling engineering, which seriously affects the progress and safety of the drilling. The current sealing measures are faced with many problems, such as the narrow pressure window, the instability of drilling fluid performance and the insignificant effect of plugging material. It is difficult to quickly and efficiently form a stable plugging zone. Taking the block of Shun Nan District as an example, the geological characteristics and the technical difficulties of sealing to control gas cut were analyzed, considering the effect of high temperature and high pressure on the field drilling fluid, and evaluation experiments were carried out by using artificial fracture core and sealing gas blocking experiment device. The indoor laboratory formed high strength composite bridge erecting material and broad-spectrum fiber material, optimized the nano material, and combined the field drilling fluid to evaluate the performance of the gas plugging material system. The compatibility of the system and the drilling fluid is good, and the gas reservoir can be blocked effectively. The recovery range of reservoir damage is more than 90%.