Evolution of diagenetic system and its controls on the reservoir quality of pre-salt dolostone: The case of the Lower Ordovician Majiagou Formation in the central Ordos Basin, China
Evolution of diagenetic system and its controls on the reservoir quality of pre-salt dolostone: The case of the Lower Ordovician Majiagou Formation in the central Ordos Basin, China
复制标题
盐下白云岩成岩系统演化及其对储层质量的控制——以鄂尔多斯盆地中部下奥陶统马家沟组为例
DOI：
10.1016/j.marpetgeo.2020.104674
复制
发表时间：
2020-08
影响因子：
4.2
通讯作者：
Tan Xiucheng
中科院分区：
文献类型：
--
作者：
Liu Mingjie;Xiong Ying;Xiong Chen;Liu Yun;Liu Ling;Xiao Di;Tan Xiucheng
成岩系统的演化及其对碳酸盐岩储层质量的影响至关重要。鄂尔多斯盆地中部下奥陶统马家沟组的新研究揭示了盐下白云岩储层的成岩作用和质量受成岩系统演化的控制。根据岩石学特征，识别出鄂尔多斯盆地中部马家沟组盐下白云岩3种不同的储层类型（颗粒、结晶、藻类白云岩）和5种不同的储集空间（粒间孔、粒内孔、晶间孔、岩溶体系溶蚀孔洞、层藻平行溶蚀孔）。盐下白云岩的成岩过程可分为准同生期成岩作用、早成岩作用、表成岩作用和中成岩作用—晚成岩作用四个阶段。对所研究的白云岩储层的岩石学和地球化学分析表明，成岩系统在准同生岩成岩作用期间是开放的，在早期成岩作用期间变得封闭。鄂尔多斯盆地中部西部和东部在表成岩过程中分别存在开放和封闭的成岩系统。此后，西部和东部盐下白云岩储层在中成岩作用—晚期成岩作用过程中均演化为封闭的成岩系统。开放成岩系统中的大气大气溶蚀（次生孔隙形成）以及随后封闭成岩系统中孔隙的保存是盐下白云岩储层质量改善的关键因素。西部白云岩储层虽然发育了从开放到封闭成岩体系的两个旋回，但在表成岩过程中，其孔隙空间被第二开放成岩体系的上覆风化泥所充填，导致储层质量下降。东部白云岩储层仅经历了开放成岩系统到封闭成岩系统的一个旋回，储层质量得到改善并得以保存。因此，只有不同成岩阶段的成岩系统之间良好匹配，才有利于储层的形成和保存。因此，盐下白云岩潜在优质储层主要分布在鄂尔多斯盆地中部东部地区。
The evolution of diagenetic system and its impact on the carbonate reservoir quality are of paramount importance. New investigation of the Lower Ordovician Majiagou Formation, central Ordos Basin, China, has revealed that the diagenesis and quality of pre-salt dolostone reservoirs were controlled by the evolution of diagenetic system. Three different reservoir types (grain, crystalline and algal dolostone) and five kinds of reservoir space (intergranular pore, intragranular pore, intercrystalline pore, dissolution pore and vug in karst system, and parallel dissolution pore of laminar algae) are identified in the Majiagou Formation pre-salt dolostone of the central Ordos Basin, based on the petrographic characteristic. The diagenetic process of pre-salt dolostone can be divided into four stages: the penecontemporaneous diagenesis, the early diagenesis, the epidiagenesis and the mesodiagenesis-late diagenesis. Petrographic and geochemical analyses of the studied dolostone reservoir indicated that the diagenetic system was open during the penecontemporaneous diagenesis and became closed during the early diagenesis. Open and closed diagenetic system existed in the west and east of the central Ordos Basin during the epidiagenesis, respectively. After that, the western and eastern pre-salt dolostone reservoirs both evolved into a closed diagenetic system during the mesodiagenesis-late diagenesis. Subaerial meteoric dissolution in an open diagenetic system (secondary pore formation), and subsequent pore preservation in a closed diagenetic system, are the critical factors in the improvement of pre-salt dolostone reservoir quality. Although two cycles from open to closed diagenetic system developed in the western dolostone reservoir, the pore space there was filled with overlying weathering mud in the second open diagenetic system during the epidiagenesis, which reduced the reservoir quality. The eastern dolostone reservoir experienced just one cycle from open to closed diagenetic system, the reservoir quality was improved and then preserved. Thus only a good match among the diagenetic systems during different diagenetic stages will be good for the reservoir formation and preservation. Therefore, the potential high-quality reservoirs in the pre-salt dolostones mainly located in the eastern part of the central Ordos Basin.
登录
查看更多内容
影响因子：
7.5
作者：
L. De-sheng
通讯作者：
L. De-sheng
影响因子：
--
作者：
R. Loucks;James H. Anderson
通讯作者：
R. Loucks;James H. Anderson
影响因子：
3.5
作者：
Baoqing Wang;I. Al-Aasm
通讯作者：
Baoqing Wang;I. Al-Aasm
影响因子：
4.2
作者：
Chaohui Liu;Q. Xie;Guiwen Wang;Wengang He;Yifan Song;Yong Tang;Yuhan Wang
通讯作者：
Chaohui Liu;Q. Xie;Guiwen Wang;Wengang He;Yifan Song;Yong Tang;Yuhan Wang
影响因子：
2.8
作者：
M. Paganoni;Amena Al Harthi;D. Morad;S. Morad;A. Ceriani;H. Mansurbeg;A. A. Suwaidi-A.;I. Al-Aasm;S. Ehrenberg;M. Sirat
通讯作者：
M. Paganoni;Amena Al Harthi;D. Morad;S. Morad;A. Ceriani;H. Mansurbeg;A. A. Suwaidi-A.;I. Al-Aasm;S. Ehrenberg;M. Sirat