The Open Petroleum Engineering Journal




(Discontinued)

ISSN: 1874-8341 ― Volume 12, 2019

An Identified Method for Lacustrine Shale Gas Reservoir Lithofacies Using Logs: A Case Study for No. 7 Section in Yanchang Formation in Ordos Basin


The Open Petroleum Engineering Journal , 2015, 8

Hongyan Yu, Zhenliang Wang, Hao Cheng, Qianqian Yin, Bojiang Fan, Xiaoyan Qin, Xiaorong Luo, Xiangzeng Wang, Lixia Zhang

State Key Laboratory of Continental Dynamics, Geology Department of Northwest University, Xi’an, P.R. China, 710069.

Electronic publication date 25/6/2015
[DOI: 10.2174/1874834120150625E012]




Abstract:

Unconventional reservoirs are keys to oil and gas exploration and development, especially shale gas reservoirs. Discriminated shale gas reservoir lithofacies are, in particular, a primary problem in shale gas reservoir engineering. The mineral composition will affect both absorbed and free gas contents, therefore their identification is important. The mineral composition is one part of lithofacies. The shale content has always been used in previous lithological identifications: this method is effective in sand reservoirs; however, it is not suitable for use in shale gas reservoirs. This paper takes No.7 section in Yanchang formation in Ordos basin as an example. Through a lithological analysis, it was concluded that overlap method and cross-plot method are not also inappropriate for shale gas reservoirs. The Ordos basin shale gas reservoir is divided into seven lithofacies. We form a mathematical method and apply it to shale gas reservoirs using the shale volume and ΔlgR which are available from conventional well logging and reflect organic matter in the processed dataset. Decision tree is used here. However, there were too many parameters to discriminate all lithofacies precisely. Principal component analysis (PCA) is a technique used to reduce multidimensional data sets to lower dimensions for analysis. This technique can be useful in petro-physics and geology as a preliminary method of combining multiple logs into a single entity or two logs without losing information. Combining PCA and a decision tree algorithm, the lithofacies of a shale gas reservoir were accurately discriminated.


Download PDF

Track Your Manuscript:


Endorsements



"I have to express my sincere appreciation for your hard and professional work. Thank you very much!"


Si Zhang
Institute for Strength and Vibration of Mechanical Structures,
Yangtze University, Jingzhou,
Hubei Province,
China

"My experiences in publishing a paper with Bentham Open is good. I must say that the speed of publication in The Open Petroleum Engineering Journal is very fast. It takes only two month for the pioneer reviewing process. The delay was caused by me. And what’s more, the publisher’s office is quite helpful. I guess they are dealing with thousands emails every week, but they process my request in a very short period of time."


Xin Ma
School of Science, Southwest Petroleum University, Chengdu, China


Browse Contents



Webmaster Contact: info@benthamopen.net
Copyright © 2023 Bentham Open