• 责任者：Yuan Guanghui (School of Geosciences and Technology ; China University of Petroleum ; Qingdao 266555 ; China) ; Cao Yingchang
• 刊名：Acta Petrolei Sinica
• 出版年：2013
• 卷期：34(5)
• 关键词：碎屑岩储集层 ; clastic reservoirs ; 东营凹陷 ; Dongying Sag
• 页码：p.853-866
• 图表：13 illus., 3 tables, 37 refs.
• 分类号：1003
• issnNo：ISSN0253-2697
• isbnNo：CN11-2128/TE

     Feldspar dissolution is an important diagenetic event in the diagenesis of Es4-middle part of Es3 clastic reservoirs in the northern slope zone of the Dongying sag. Secondary dissolved pores of feldspar grains are almost ubiquitous in clastic reservoirs, however, microscopic investigations indicate that the stronger the feldspar dissolution, the richer the dissolution products, thus, whether physical property of a reservoir can be effectively improved though feldspar dissolution remains debatable. Based on matched thin sections and molded thin sections, we accurately counted amounts of both feldspar dissolution and dissolution products of rock thin sections using area percent method and humar~ computer interaction image analysis technique. Combined with reservoir property, liquid inclusion testing and pore structure data matched with rock thin sections, we systematically analyzed characteris- tics of feldspar dissolution and dissolution products, diagenetic environment of feldspar dissolution and its impact on physical properties of Es4-middle part of Es3 clastic reservoirs in the northern slope zone, Dongying sag. The result showed that feldspar dissolution in the studied reservoirs occurred in a relatively closed and high temperature diagenetic environment, dissolution prod ucts could not be effectively brought out the dissolved area or moved in a long distance due to a low speed of fluids in the pore net- work system and a quicker dissolution of feldspars under high temperatures, instead, they precipitated only in situ or almost in situ. In other words, feldspar dissolution just transformed primary intergranular pores with better pore structures to secondary pores of feldspar grains with an almost identical volume but poorer pore structures as well as to kaolinite （illite） intercrystal pores. Before and after dissolution, reservoir porosity changed little, but reservoir structure became poorer after dissolution and so was res- ervoir nermeabilitv.