苏里格气田西南部致密砂岩气藏资源评价方法及评价参数的影响因素

对储层特征及其对资源评价影响的认识，是致密砂岩气藏资源评价、生产和高效开发的基础之一。通过测井分析、薄片观察、生烃条件和生产数据分析，研究苏里格气田西南部石盒子组8段和山西组1段储层特征、砂体展布、砂体厚度、砂体叠置模式，明确储层特征和适用的评价方法，探讨储层特征对资源评价参数的影响。研究表明：苏里格气田储层具有典型的低孔低渗、强非均质性特征，适用容积法进行资源评价；储层厚度和面积受控于砂体展布和叠置模式，一般砂体厚度大，展布面积广的分流河道和复合砂体的资源量较大，产气量较高；储层孔渗受控于碎屑组分和微观孔隙类型，并受后期成岩作用强烈改造，压实作用和胶结作用破坏孔隙，溶蚀作用有力地改善了孔隙；生烃强度在根本上控制了产水区和产气区的分布，而致密气富集的甜点区主要分布于有利储层的相对高孔渗部位。在致密砂岩气资源评价中，沉积作用控制了砂体展布和叠置模式，塑造了不同类型的复合砂体，决定了储层面积、厚度，进而控制了油气赋存规模和产能。成岩作用改变储层储集和渗滤性能，主要以微观形式来对整个油气开采区的油气储量带来影响。

Resource evaluation method and influence factors of its parameters for tight sand gas reservoir in southwestern Sulige gas field

The research on reservoir characteristics and their impact on resource assessment is one of the bases for tight gas resource evaluation, production and efficient development.An integration of analyses of logging data, hydrocarbon generation conditions and production data, as well as thin section observation, is applied to investigate the reservoir characteristics, the distribution, thickness and superposition pattern of sand bodies in He 8 member and Shan 1 member in southwestern Sulige gas field, to select an applicable evaluation method according to the reservoir characteristics, and to explore the effect of reservoir characteristics on evaluation parameters.The results show that the reservoirs in Sulige gas field are characterized by low porosity, low permeability and strong heterogeneity, thus the volumetric method is suitable for its resource evaluation.The reservoir thickness and area are controlled by the distribution and superimposition pattern of sand bodies, and the distributary channels and composite sand bodies with large thickness and area are usually high in resource potentials and more productive.The reservoir porosity and permeability are controlled by debris composition and microscopic pore type, and are strongly modified by diagenesis at later stages.Compaction and cementation lower porosity, whereas dissolution may effectively increase it.The intensity of hydrocarbon generation fundamentally controls the distribution of the water producing zone and gas producing zone, while the sweet spots of tight gas are mainly located in areas of relatively high porosity and permeability in favorable reservoirs.For resource evaluation of tight sand gas reservoirs, the sedimentation controls the distribution and superimposition patterns of sand bodies, produces composite sand bodies of various types, determines reservoir area and thickness, and then controls the gas storage potential and production capacity.Diagenesis modifies reservoir porosity and permeability, thus mainly influences oil and gas reserves of the study area in a microscopic sense.