广西雪峰山南缘石炭系寺门组储层特征及其控制因素

Reservoir characteristics and controlling factors of the Carboniferous Simen Formation at the southern margin of Xuefeng Mountain， Guangxi Zhuang Autonomous Region， China

刘自亮 张明何 刘四兵 王均杰 郝景宇 陈义才 周月

Ziliang Liu Minghe Zhang Sibing Liu Junjie Wang Jingyu Hao Yicai Chen Yue Zhou

广西雪峰山南缘石炭系寺门组具有较好的油气成藏背景条件，查明寺门组储层的形成发育机制及其控制因素对该区油气勘探具有重要意义。利用野外露头、钻井和岩心资料，结合运用扫描电镜、铸体薄片、包裹体和孔-渗分析等手段，明确了广西雪峰山南缘石炭系寺门组储层的基本特征，探讨了储层发育的控制因素及优质储层形成模式和有利区分布。研究表明，寺门组储层岩石类型主要为细粒石英砂岩和岩屑质石英砂岩；储集空间包括原生粒间孔、次生溶蚀孔和裂缝；储层类型属于孔隙-裂缝型和孔隙型，整体呈低孔、低渗特征。储层质量主要受沉积、成岩及构造作用的共同控制：沿岸砂坝、砂泥质滨岸和混合坪微相控制了寺门组储层砂体的分布；强烈的压实作用是储层致密化的最主要原因，造成的孔隙损失率约85.2 %；溶蚀作用使储层质量得到有效提升（增孔量约2.3 %）；构造裂缝极大地促进了储层的输导能力，使局部地区仍具备优质储层发育的物性条件。最后，建立了储层发育模式，预测研究区存在德胜和洛埠2个有利储层分布区。

The Carboniferous Simen Formation located at the southern margin of Xuefeng Mountain in Guangxi Zhuang Autonomous Region of China is of good hydrocarbon accumulation conditions. It is of great significance to finding out the formation and development mechanism and controlling factors of Simen Formation reservoirs regarding the petroleum exploration therein. An integration of field outcrop observation and various data including drilling and core， scanning electron microscopy （SEM）， casting thin section， inclusions， as well as porosity and permeability， is applied to clarify the basic characteristics of the Carboniferous Simen Formation reservoir at the southern margin of Xuefeng Mountain； and meanwhile the factors controlling reservoir development， formation mode of high-quality reservoirs， and distribution of play fairways are discussed. The research results show that the reservoir rocks of Simen Formation mainly include fine-grained quartzite sandstone and detrital quartzite sandstone， which are dominated by reservoir spaces of primary intergranular pores， secondary dissolved pores and fractures. The reservoirs are of the pore-fracture type and pore type， characterized by low porosity and low permeability as a whole. On the other hand， sedimentation， diagenesis and tectonism jointly control the reservoir quality， that is， microfacies of coastal sand bar， sandy-argillaceous shore and mixed flat control the distribution of reservoir sand bodies in the Simen Formation. Strong compaction is the primary cause for tight reservoirs， which could result in a pore loss rate of about 85.2 %， while dissolution effectively improves the reservoir quality （with a porosity rise of about 2.3 %）， and structural fractures greatly promote the carrier system of the reservoirs with some areas still favorable for the development of high-quality reservoirs in terms of physical conditions. Finally， a model for the reservoir development is established， by which two favorable areas for reservoir distribution of Desheng and Luobu counties are mapped in the study area.

10.11743/ogg20220413