摘要
川西深层致密碎屑岩储层属低孔低渗、致密超致密储层,储层包括孔隙性、裂缝性、裂缝—孔隙型三类储层,其中裂缝—孔隙型储层是目前获得较高产量的主产层。因此,其裂缝的有效性评价及储层中的含气性识别是川西深层致密碎屑岩储层评价的关键所在。针对储层特征及储集空间类型,首先确定储层的基质孔隙度下限;再根据储层中裂缝的充填及溶蚀程度、构造应力场的变化程度、裂缝走向与现今主地应力方向的匹配关系、斯通利波的能量衰减与反射、钻井过程中的井漏显示等来评价裂缝系统是否有效;通过泊松比与岩石体积压缩系数交会法、核磁共振差谱与移谱法及井温异常法等对该类储层进行含气性判别。该方法弥补了以往用电阻率、中子等常规测井来判断储层流体性质的缺陷,在川西深层致密碎屑岩储层综合评价中应用效果显著,从而形成了一套针对致密碎屑岩储层更有效的测井评价方法。
The tight clastic reservoirs in the deep of western Sichuan Basin are characterized by low porosity and low permeability,and belong to tight to super-tight reservoirs.Three types of reservoirs are identified,including porous,fractured,and fractured-porous reservoirs,among which the fractured-porous reservoirs are the major pay zones.Therefore,evaluation of fracture effectiveness and identification of gas-bearing property are critical to the evaluation of reservoirs in the study area.First,the lower limit of matrix porosity is defined according to reservoir features and reservoir space types.Then the effectiveness of fractures is evaluated with various parameters,such as the filling and dissolution of fractures,the change of tectonic stress field,the relationship between fracture orientation and principal stress direction,the attenuation and reflection of Stoneley wave,and the lost circulation during drilling.Various methods,including the crossplot technique of Poisson's ratio vs.volume compressibility,NMR differential and shifted methods,and anomalies in well temperature logging,are used to identify gas-bearing properties of these reservoirs,and they can overcome the disadvantages of conventional logging technologies.They have been successfully applied to the comprehensive evaluation of the tight clastic reservoirs in the deep of western Sichuan Basin.
出处
《天然气工业》
EI
CAS
CSCD
北大核心
2010年第1期31-35,共5页
Natural Gas Industry
关键词
四川盆地
西
碎屑岩
致密层
储集层
裂缝
测井
评价
Sichuan Basin,west,clastic rock,tight layer,reservoir,fracture,log,evaluation
