海上低渗气藏高矿化度入井流体储层敏感性研究

Study on Reservoir Sensitivity of High Salinity Inflow Fluid in Offshore Low Permeability Gas Reservoir

评价高矿化度入井流体储层敏感性对于海上油气藏压裂液研发至关重要,由于海上压裂作业具有较强的特殊性,从钻开储层至压裂作业的时间周期较短,无法及时进行储层敏感性评价会造成压裂液体系设计不准确,对压裂效果造成较大影响。基于此,通过开展室内实验评价了东海某低渗气藏高矿化度入井流体的储层敏感性,结果表明:东海某低渗气藏具有强水敏、强盐敏、弱酸敏和弱碱敏的储层敏感性,而孔喉空间小和比表面大产生的水相滞留是导致储层强水敏的主要原因,盐结晶堵塞则是导致储层强盐敏的主要原因。该结果可为东海某低渗气藏压裂液研发提供强有力的技术支撑。

Evaluating the reservoir sensitivity of highly mineralized fluids is crucial to the research and development of fracturing fluids in offshore reservoirs.Due to the strong particularity of offshore fracturing operations,the time period from drilling to fracturing operations is short,and failure to timely evaluate the reservoir sensitivity will lead to inaccurate fracturing fluid system design,which will greatly affect the fracturing effect.Based on this,the reservoir sensitivity of highly mineralized fluid in a low permeability gas reservoir in the East China Sea was evaluated through laboratory experiments.The results show that:A low permeability gas reservoir in the East China Sea has strong water sensitivity,strong salt sensitivity,weak acid sensitivity and weak alkali sensitivity.The water phase retention caused by small pore throat space and larger than surface is the main reason for the strong water sensitivity of the reservoir,and the salt crystallization blockage is the main reason for the strong salt sensitivity.The results can provide strong technical support for the research and development of fracturing fluid for a low permeability gas reservoir in the East China Sea.