定边地区辫状河沉积储层主控因素

(1.长安大学 地球科学与资源学院,陕西 西安 710054; 2.延长油田股份有限公司 定边采油厂,陕西 定边 718600)

辫状河储层; 定边地区; 沉积作用; 成岩作用

Main controlling factors of braided river sedimentary reservoir in Dingbian Area
QU Wei-dong1,FU Chao-feng1,AN Shan2,WANG Tao1,ZHU Jin-jin1,DU Chen1

(College of Earth Science and Resources,Chang'an University,Xi'an 710054 China; 2.Dingbian Oilfield,Yanchang petroleum Co.,Ltd.,Dingbian 718600,China)

braided river reservoir; Dingbian area; sedimentation; diagenesis

DOI: 10.13800/j.cnki.xakjdxxb.2019.0110

备注

辫状河储层的储集能力是由储集层的岩石性质所决定,包括孔隙度和渗透率,其中孔隙度决定储层的储存能力,渗透性决定储层的渗流能力。应用沉积学、石油地质学及储层地质学等学科,结合测井、岩心观察及分析化验等资料,系统的研究了定边地区辫状河储层沉积特征及主控因素。研究表明:定边地区延10油层组的岩石类型主要为岩屑石英砂岩、长石石英砂岩以及少量的石英砂岩; 孔隙度主要分布于13.9%~17.5%,渗透率多集中于10~16×10-3 μm2,属中孔低渗储层; 孔隙类型主要为粒间孔; 储层类型属中孔、细喉型,排驱压力和中值压力相对较低; 定边地区辫状河储层明显受控于沉积作用和成岩作用,其中,储层的砂体类型、厚度及展布和岩石学特征主要受沉积作用的影响,储层的储集能力主要受成岩作用的影响,压实作用和胶结作用会使储层的储集能力变差,而溶蚀作用会使储层的储集能力变好。

The capacity of braided river reservoirs is determined by the rock physics of the reservoir,including its porosity and permeability; porosity determines the reservoir storage capacity,and permeability determines the reservoir seepage capacity.Based on the sedimentology,petroleum and reservoir geology,combined with logging,core observations,and core analysis,the sedimentary characteristics and main controlling factors of braided river reservoirs were studied.The results show that the rock types are mainly lithic quartz sandstone,followed by feldspar quartz sandstone and a small amount of quartz sandstone.The porosity is mainly distributed at 13.9%~17.5%,permeability is mostly concentrated in10~16 ×10-3 μm2,belonging to middlepore with low permeability; pore type is mainly intergranular pores; reservoir type is a middle pore,fine throat type.Expulsion and median pressure is relatively low; the physical properties of the braided river reservoir are obviously controlled by the sedimentary and diagenesis.The sand body type,thickness,distribution and petrological characteristics of the reservoir are mainly affected by sedimentation,and the reservoir capacity is mainly affected by the diagenesis.But the compactionand cementation will make the reservoir capacity worse,and the dissolution will make the reservoir better.