安棚深层系扇三角洲低渗致密砂岩储层综合评价

泌阳凹陷安棚深层系主要指埋深大于2800m左右以核三下亚段为主的勘探目的层系，属扇三角洲沉积。砂岩储层的孔隙结构明显分为两大类，反映了以填隙物晶间孔隙为主的和以有效孔隙及裂缝为主的两种孔隙介质的孔隙结构特点。孔喉分布状况差，结构复杂，喉道微细且不均匀，致密低渗是该套储层突出特点。快速堆积，颗粒大小混杂，分选差，成分成熟度和结构成熟度低，是导致深层系砂岩低渗的主要原因；成岩作用，特别是压实作用和晚期碳酸盐胶结作用是影响储层微观非均质性和导致储层致密低渗的主要因素。综合研究可将砂岩储层划分为三类，其中Ⅰ、Ⅱ类为深层系有效油气储层，Ⅲ类储层为无效储层，但可作为有效储气层。根据孔隙度、声波时差随深度的变化关系及孔隙度、渗透率的平面展布特征，结合试验资料及微相平面展布，对深层系储层类型纵向和平面分布进行了综合评价。

Integrated Evaluation of Fan Delta Compacted and Low Permeable Sandstone Reservoir of Anpeng Deep Zone

Anpeng deep zone reservoir in Biyang Depression is usually buried in the zone deeper than 2800 meters, of which its target bed in the lower section of Es 3 of Hetaoyuan Formation is a fan-delta sedimentary system. The pore structure of sandstone reservoir is divided into two kinds obviously, one represents the pore structure and porous medium mainly having the character of inter-crystal pore, the other represents the pore structure and porous medium mainly having the character of effective pores and cracks .Characters of the reservoir are poor in pore throat distribution , complex in structure , small and heterogeneous in throat as well as compaction and low permeability. Rapid accumulation, sophistication of different grain sizes, low maturation of texture and component are the key factors of low permeability. The diagenesis, especially the compaction and the later carbonate cementation are the key factors affecting the microheterogeneity of the reservoir and leading the reservoir compaction and low permeability. The integrated study shows that the deep reservoir would be divided into three types, type I and II are an effective oil and gas reservoir , type III is an ineffective oil reservoir, but it would be an effective gas reservoir. According to the function of porosity , interval transit time changing with depth and the characteristics of horizontal distribution of porosity and permeability, vertical and horizontal distribution of deep reservoir is evaluated integratedly in combination of testing data and horizontal microfacies distribution.