Structural Features of Unconformities: A Case Study of the Jurassic-Cretaceous Unconformity in Well Yong 1 Area,Junggar Basin

doi:10.19657/j.geoscience.1000-8527.2019.02.15

Abstract

Abstract:

Well Yong 1 area is located in the Changji Sag of the Junggar Basin. Yanshan Movement had formed the Chemo uplift in the mid-late Jurassic, and it also led to overlapping and erosion of the Xishanyao Formation, forming a series of stratigraphic and lithologic reservoirs. Unconformity structures play an important role in the hydrocarbon migration and accumulation processes. Considering the factors of accumulation, the unconformity structures are divided into three levels: Level I includes cover and unconformity body, Level II divides the unconformity body into overlying strata, unconformity layer and underlying strata, and Level III contains the reservoir-forming elements, including the reservoir, barrier layer, weathered claystone and weathered leaching zone. The vertical unconformity structures are divided by logging data based on lithology, physical properties and petrological characteristics, and these structures in the study area are relatively complete. Through natural gamma ray inversion (based on seismic and well-logging data), the distribution of reservoirs and barriers in the unconformity structural layers are clarified. Thickness of the weathered leaching zone decreases gradually from the upper part to the sag, whereas the weathered claystone thickness increases, yielding a good negative correlation. The unconformity structures control the two most important types of reservoir-cap combinations in this area, i.e. (1) a combination of the overlying strata and the regional cap layer, and (2) a combination of the underlying strata and the weathered claystone.

Key words: unconformity body, structural feature, reservoir cap assemblage, Well Yong 1 area

CLC Number:

TE122

GUAN Wei, XU Huaimin, LI Han, CHENG Lei, MA Yonghui. Structural Features of Unconformities: A Case Study of the Jurassic-Cretaceous Unconformity in Well Yong 1 Area,Junggar Basin[J]. Geoscience, 2019, 33(02): 401-411.

Figures/Tables 13

Fig.1 Location and structural map of Well Yong 1 area

Fig.2 Diagram showing the unconformity structural pattern

Fig.3 A N-S seismic interpretation profile of the Jurassic Xishanyao Formation in Well Yong 1 area

Fig.4 Planar distribution of the Jurassic Xishanyao Formation pinch out in Well Yong 1 area

Fig.5 Division of vertical unconformity structures in Well Yong 1 area

Fig.6 Reservoir thickness prediction for the overlying strata by natural gamma inversion in Well Yong 1 area

Fig.7 Relation diagram of the elemental content and depth of the mudstone in Well Yong 1

Fig.8 Profile of the unconformity body vertical structural division (profile location shown in Figure 1)

Fig.9 Planar contour map of the weathered clay layer in Well Yong 1 area

Fig.10 Relationship between feldspar content and porosity and depth beneath the unconformity of Well Yong 1

Fig.11 Microphotographs dissolution features beneath the unconformity of Well Yong 1

Fig.12 Reservoir thickness prediction in the underlying strata by natural gamma inversion in Well Yongl area

Fig.13 Planar contour map of the weathered leaching zone in Well Yong 1 area

References 18

[1]	吴孔友, 李林林, 查明. 不整合纵向结构及其成藏作用物理模拟[J]. 石油实验地质, 2009,31(5):537-541. DOI URL
[2]	郭泽清, 刘卫红, 张林, 等. 中国陆相岩性地层油气藏分布规律和控制因素研究进展[J]. 地质科技情报, 2009,28(5):71-77.
[3]	范忠礼, 张广雪, 孙中强, 等. 准噶尔盆地永进地区白垩系清一段沉积相研究[J]. 中国海洋大学学报(自然科学版), 2015,45(8):83-89.
[4]	HUTTON J X. Theory of the Earth; or an investigation of the laws observable in the composition, dissolution, and restoration of land upon the globe[J]. Environmental Science Transactions of the Royal Society of Edinburgh, 1788,1(2):209-304.
[5]	周新平. 塔里木盆地塔中石炭系不整合复合体油气成藏规律与评价研究[D]. 北京:中国石油大学(北京), 2013.
[6]	杨勇, 查明. 准噶尔盆地乌尔禾-夏子街地区不整合发育特征及其在油气成藏中的作用[J]. 石油勘探与开发, 2007,34(3):304-309.
[7]	陈中红, 查明, 吴孔友, 等. 陆梁隆起白垩系底部不整合面特征与油气运聚[J]. 新疆石油地质, 2002,23(4):283-285.
[8]	吴孔友, 李林林, 查明. 不整合纵向结构及其成藏作用物理模拟[J]. 石油实验地质, 2009,31(5):537-541. DOI URL
[9]	曲江秀, 查明, 田辉, 等. 准噶尔盆地北三台地区不整合与油气成藏[J]. 新疆石油地质, 2003,24(5):386-388.
[10]	洪太元, 蔡希源, 何治亮, 等. 准噶尔盆地腹部白垩系底部不整合特征[J]. 新疆地质, 2006,24(3):229-233.
[11]	王艳忠, 操应长, 王淑萍, 等. 不整合空间结构与油气成藏综述[J]. 大地构造与成矿学, 2006,30(3):326-330.
[12]	李琳琳. 济阳坳陷中生界不整合纵向结构及控藏作用研究[D]. 北京:中国石油大学(北京), 2009.
[13]	周新平, 徐怀民, 王仁冲, 等. 准噶尔盆地侏罗系不整合复合体及其岩性地层油气藏[J]. 现代地质, 2012,26(3):581-588.
[14]	史建南, 邹华耀, 李平平, 等. 准噶尔盆地永进地区油气成藏主控因素分析[J]. 中国矿业大学学报, 2009,38(3):384-389.
[15]	胡海燕, 李平平, 王国建. 准噶尔永进地区深层次生孔隙带发育机理[J]. 地质科技情报, 2008,27(3):21-25.
[16]	洪太元. 准噶尔盆地腹部白垩系底部不整合特征及其控油作用研究[D]. 北京:中国地质大学(北京), 2006.
[17]	何登发. 不整合面的结构与油气聚集[J]. 石油勘探与开发, 2007,34(2):142-149.
[18]	王芙蓉, 何生, 何治亮, 等. 准噶尔盆地腹部永进地区砂岩储层中碳酸盐胶结物特征及其成因意义[J]. 岩石矿物学杂志, 2009,28(2):169-178.