陵水17-2气田深水测试液类型选择

南海北部深水区陵水17-2气田储层地层压力系数1.19~1.21、孔隙度平均值为31.5%,渗透率平均值为633×10-3 μm2,储层孔渗关系好;黏土含量为16.1%,具有盐敏、水敏等特点。对该气田测试液类型进行了优选:氯化钙海水溶液、甲酸钾海水溶液和100%络合水3种基液均能满足密度在1.28~1.30 g/cm3内可调的要求;均具有较好的抑制性,防膨率均在95%左右;3种基液抑制气体水合物生成的浓度低限为28.06%氯化钙、51.05%甲酸钾和72.00%有机醇,因此甲酸钾基液抑制气体水合物生成的能力不足;氯化钙基液矿化度高,具有盐敏潜在损害;络合水自身具有较好的防水锁性,表面张力约为25 mN/m,而氯化钙和甲酸钾基液的表面张力较大。最终优选100%的络合水作测试液基液。其在陵水17-2-1井进行了应用,测试后产量为160×104 m3/d,表皮系数为0.2,储层保护效果好。

Analysis of Causes of Reservoir Damage in Lingshui 17-2 Gas Field and Selection of Test Fluid for Reservoir Protectionin Deep Water Area

Lingshui 17-2 gas field in the deep water area in South China Sea has reservoir formations that are controlled by these parameters:formation pressure coefficient 1.19, average porosity 31.5%, range of permeability 0.08×103 μm2-2.512×103 μm2, averaged at 633×103 μm2, and clay content 16.1%.The porosity has regular relation with permeability, and the clay is sensitive to salt contamination and water flow.When transfer an exploration well to a production well, the test fluid to be used shall satisfy these needs such as balancing the formation pressures, inhibiting the generation of gas hydrates, and protecting reservoirs.A test fluid formulated with "aquo complex" was used in the gas field, giving gas production of 1.60×106 m3/d, and skin factor as low as 0.2.