二次加砂压裂技术在海上低孔渗砂岩气藏的应用

东海低渗储层具有埋藏深、温度高、边底水发育、平台空间小等特点,采用传统加砂压裂方式初期产量低、压后压降快、有效产能低,无法满足海上经济有效开发的需求。因此,基于平台化压裂的技术瓶颈,开展二次加砂压裂增产机理及适应性评估,通过技术优化研究,确定了二次加砂压裂施工排量、加砂规模、二次加砂比例、中途停泵时间等关键参数,优选评价了压裂液和支撑剂材料,并评估了平台空间综合利用,形成了一种适合海上低渗平台开发的增产技术。DX-B5井的实施效果表明:二次加砂压裂技术首次应用于海上低渗油气田,并取得显著的增产效果,相比邻井初期产量增加了2倍,累计产量增加了3倍,针对类似储层条件的油气井,可推广应用于东海及国内其他海域的低渗储层增产开发。

Application of secondary sand fracturing technique in offshore low porosity and permeability sandstone gas reservoir

Low permeability gas reservoir in East China sea are characterized by deep burial, high temperature, edge and bottom water development, and small platform space. The traditional sand fracturing method was low initial production, fast pressure drop after pressure, and low effective productivity, which cannot meet the requirements of effective development of offshore economy. Therefore, based on the platform of fracturing technology bottleneck, carrying out secondary sand fracturing stimulation mechanism and adaptability evaluation, and through technology optimization research, it determined the key parameters which includes secondary sand fracturing operation, sand displacement scale, the proportion of secondary sand, midway stop pump time. The fracturing fluid and proppant materials were optimized and evaluated, and the comprehensive utilization of platform space was evaluated, which forms a stimulation technology suitable for offshore low-permeability platform development. DX-B5 Wells effect shows that the secondary sand fracturing technique is the first application at offshore low permeability oil and gas fields, and achieves remarkable stimulation effect, which compared with the adjacent Wells early output has increased by 2 times, total output increased three times. For similar reservoir conditions of oil and gas Wells, it can be applied to East China sea and other domestic waters of low permeability reservoir development to increase production