大川中地区长兴组储层特征分析

Analysis on the Characteristics of Changxin Formation Reservoir in the Dachuanzhong Area

摘要: 针对大川中地区长兴组气藏勘探程度低、储层发育特征认识程度不高的问题，本文从长兴组地层发育的构造特征、地层展布特征、岩石学特征及测井响应特征等方面对长兴组储层特征进行了分析。认为研究区长兴组储层由于受2个台内高带和高带之间的凹地的影响，发育有泥–微晶灰岩、生物碎屑灰岩、砂屑灰岩以及生物礁灰岩等岩性。生屑灰岩、生物礁灰岩储层在研究区并不是广泛分布，而是呈点状的形式展布。储层总体上表现为低孔低渗储层，储集空间主要为孔型储层，局部发育裂缝–孔隙型储层。储层的测井响应较为明显，从孔隙度测井及电阻率测井上易于识别，表现为孔隙度曲线和电阻率曲线形状多呈“U”或“W”字型变化，很少呈现厚度小的尖刺状“V”字型特征。

Abstract: In view of the questions in the mountain regions of Changxing group that gas reservoir exploration degree is low and that the development features of reservoir cognition degree are not high, from the Changxing formation and development of tectonic characteristics, characteristics of formation distribution, petrological characteristics and characteristics of logging response, this article analyzed the reservoir characteristics of Changxing group. Due to the two stages between highlands and the influence of the craters in highlands, mud-microcrystalline limestone, bioclastic limestone, calcarenite and biological reef limestone rocks are developed in the study area of Changxing group reservoir. Raw crumb limestone and biological limestone reef reservoir are not widely distributed in the study area, but in the form of dotted distribution. Reservoirs are generally characterized by low porosity and low permeability reservoir. The reservoir space is mainly for the groove reservoir, locally developed for the fracture-pore type reservoir. The logging response is more obvious, easily recognized from logging, and it shows that the curve shapes of the resistivity and porosity form a “U” or “W” type change, and rarely present thickness and small spikes of “V” characteristics.