姬塬地区上三叠统长6油层组储层成岩相研究

综合运用铸体薄片和扫面电镜等技术方法研究鄂尔多斯盆地姬塬地区侏罗系延长组长6油层组的成岩作用和成岩相带,结果表明研究区长6油层组的储层物性较差,岩性以细粒长石砂岩和岩屑长石砂岩为主,成分成熟度低,结构成熟度中等;储层砂体目前主要处于中成岩阶段A期-B期,压实作用使原始孔隙度降低,钙质胶结和硅质胶结破坏原生孔的同时也减少了次生孔,绿泥石环边胶结有效的保存了原生粒间孔,后期的溶蚀作用对储层物性有所改善.依据成岩作用对储层的影响,划分出4种成岩相：与水下分流河道砂体有关的绿泥石环边残余孔相,与水下分流河道砂体边部和分流间湾有关的黑云母压实相、碳酸盐胶结相和高岭石弱溶蚀相.

Study on the diagenetic facies characteristics of Chang 6 reservoir of the Upper Triassic Yanchang formation in Jiyuan area

Based on the study on casting thin sections and scanning electron microscope,this paper discusses the diagenesis and diagenetic facies of Chang 6 interval of Upper Triassic in Jiyuan area.Research shows that Chang 6 interval has poor physical properties,mainly con- sisting of fine debris-feldspar sandstone and feldspar sandstone with low component maturity and middle structure maturity.Reservoir is in the A-B period of diagenetic stage,primary pore decreasing by compaction,calcite and siliceous cementation not only destroying primary pore but also lowering secondary pore,rim cementation of chlorite effectively preserving pri- mary pore and the later dissolution to some extent improving reservoir physical property.Ac- cording to the diagenesis effect on reservoir,it marks off four diagenetic facies related to cor- responding sedimentary facies：chlorite rim residual hole facies related to underwater distribu- tive river course sands,biotite compaction facies related to margin of underwater distributive river course sands and distributary interchannel,carbonate cement facies and kaolinite weak- dissolution facies.