Utilizing borehole electrical image and conventional logs to characterize petrology of mixed volcanic and sedimentary ro
- PDF / 30,719,210 Bytes
- 17 Pages / 595.276 x 790.866 pts Page_size
- 60 Downloads / 162 Views
ORIGINAL PAPER
Utilizing borehole electrical image and conventional logs to characterize petrology of mixed volcanic and sedimentary rocks in Jiamuhe Formation at JL2 Wellfield, Zhongguai Uplift, Junggar Basin, NW China Rui Yuan 1,2 & Lei Zhang 3 & Qinghai Xu 4 & Youlun Feng 3 & Zhiyuan An 3 & Jun Wu 3 & Kang Zhao 4 & Shuai Liu 4 & Peng Huang 4 Received: 3 June 2020 / Accepted: 7 October 2020 # Saudi Society for Geosciences 2020
Abstract Lower Permian Jiamuhe Formation of JL2 Wellfield, Zhongguai Uplift, Junggar Basin, was constituted by mixed volcanic and sedimentary rocks. The rock types were various, and it is difficult to characterize the petrology just relying on limited cores in oilbearing intervals. Based on core photos, petrological characteristics were synthetically interpreted using borehole electrical image and conventional logs in this paper. Six types of common volcanic rocks (rhyolite, dacite, andesite, basalt, tuff, and breccia) and three types of clastic sedimentary rocks (conglomerate, sand, and silt-clay) were represented by borehole electrical image log and conventional natural gamma ray (GR), resistivity (RT), neutron (CNL), and bulk density (DEN) logs. Two special volcanic textures, pillow structure and natural fracture, were also described in electrical images. Serial cross-plots in pairs of four conventional logs were formed to distinguish typical rocks, and the distinction between volcanic breccias and sedimentary conglomerates was analyzed in electrical images. Borehole electrical image and conventional logs can be efficiently used to supplement coring and petrological information, which provides important insights on the paleogeology of mixed volcanic and sedimentary rocks in Jiamuhe Formation at JL2 Wellfield. Keywords Borehole electrical image log . Petrological characterization . Volcanic rocks . Sedimentary rocks . Jiamuhe Formation . JL2 Wellfield
Introduction Responsible Editor: Santanu Banerjee * Qinghai Xu [email protected] Rui Yuan [email protected] 1
Key Laboratory of Exploration Technologies for Oil and Gas Resources (Yangtze University), Ministry of Education, Wuhan 430100, Hubei, China
2
School of Information and Mathematics, Yangtze University, Jingzhou 434023, Hubei, China
3
Research Institute of Exploration and Development, Xinjiang Oilfield Company, PetroChina, Karamay, Xinjiang 834000, China
4
School of Geoscience, Yangtze University, Wuhan 430100, Hubei, China
Petrological characterization of buried formation is the foundational work in petroleum geology. Drilled cores, the only available real rocks in wells, are the powerful evidences to understand the geological information. However, for high cost and long time, cores are usually sampled in key reservoir intervals at significant exploratory wells. The petrological characterizations of uncored intervals have to be depended on open hole well logs. The conventional logs are the most extensive data which record formation attributes in onedimensional digit curves (Schlumberger 1991; Darling 2005).
