巴麦区块泥盆系超低渗储层敏感性试验研究

Experimental Study of Sensitivity of Ultralow Permeability Reservoir for Devonian System of Bachu-Maigaiti Block

为了研究巴麦区块泥盆系超低渗储层的储层敏感性,通过油水分析、岩心分析(扫描电镜、X射线衍射、铸体薄片、压汞)和岩心敏感性评价试验,指出巴麦区块泥盆系储层临界流速0.028644m/d,为弱速敏;中等偏强水敏;临界矿化度35125.73mg/L,极强盐敏;无酸敏和碱敏;强应力敏感,临界压力为6.9MPa。指出酸化对储层改善有很好的效果,钻完井液体系需要较强的抑制性能、较低的失水量及适当的矿化度,要优选性能优良的包被抑制剂、抗高温降滤失剂、无机电解质;加入成膜剂、可充填变形离子提高储层的有效应力支撑,防止应力造成的储层损害。

In order to study the sensitivity of ultralow permeability reservoir for Devonian system of Bachu-Maigaiti block,through oil/water analysis,core analysis(SEM,X-ray diffraction,thin slice,mercury penetration) and evaluation test of core sensitivity,pointed out the sensitivity of ultralow permeability reservoir for Devonian system of Bachu-Maigaiti block is that: critical flow velocity is 0.028644m/d,weak velocity sensitivity;medium to strong water sensitivity;critical salinity 35125.73mg/L,very strongly salt sensitivity;no acid sensitivity and alkali sensitivity;very strongly stress sensitivity,breakdown pressure is 6.9MPa.Acid treat is good to improvement of reservoir.The drill fluid and completion fluid require strong rejection capability,low water loss and reasonable salinity;optimize well-behaved cladding depressant,fluid loss agent of high temperature defying,inorganic electrolyte;join film forming agent and fillabled deformation ion to improve reservoir's actual stress backup,avert reservoir damage aroused by stress.