顺北一区裂缝性碳酸盐岩储层抗高温可酸溶暂堵技术

Acid-Soluble Temporary Plugging Technology for Ultra-Deep Fractured Carbonate Reservoirs in Block 1 of the Shunbei Area

顺北油气田一区超深裂缝性碳酸盐岩储层具有高温、高压和天然裂缝发育的特点,钻井过程中易发生漏失。为了解决地层漏失及漏失后带来的储层损害问题,基于岩石矿物组成、微观结构特征和损害因素等研究,提出了"钻井液性能控制+可酸溶暂堵体系"的储层保护对策,研制了主要由可酸溶纤维、可酸溶填充材料及弹性石墨组成的抗高温可酸溶暂堵体系。试验结果表明,该暂堵体系抗温180℃,酸溶率大于85.0%,渗透率恢复率大于87.0%,适用于缝宽1.0 mm以下的裂缝性储层。SHB1-10H井的现场试验表明,其目的层钻进中采用抗高温可酸溶暂堵技术后,储层保护效果明显,投产后产油量达到90.0 m3/d,较邻井产油量大幅提高,实现了"堵得住、解得开",为类似油田的裂缝性储层高效钻进提供了一种新的技术途径。

Ultra-deep fractured carbonate reservoir in Block 1 of the Shunbei Oil and Gas Field can be characterized by high temperatures,high pressure and developed natural fractures that is easy to cause mud loss in drilling.In order to solve the problem of circulation loss and formation damage after drilling fluid leakage,a high temperature resistant acid-soluble temporary plugging technology was developed.The technology mainly consists of high acid-soluble fiber,acid-soluble filling materials with different size and elastic graphite.Through the research on rock mineral composition,microstructure characteristics and damage factors,the reservoir protection strategy of“mud property control+acid-soluble temporary plugging”in Shunbei was put forward.The application results show that the temporary plugging system has a fairly good performance with temperature rating of 180℃,acid dissolution rate over 85.0%and permeability recovery rate over 87.0%,which is suitable for fractured reservoirs with fracture widths less than 1.0 mm.It is shown from field pilot of targeted formations in Well SHB1-10H that reservoir protection are apparently improved after the application of acid-soluble temporary plugging technology,and the oil production rate has been dramatically increased compared with offset wells,with oil production reaching 90.0 m3/d.It has achieved either plugging or breaking-down,which provides a new temporary plugging technique for efficient drilling in fractured reservoirs.