Xinjiang Petroleum Geology ›› 2024, Vol. 45 ›› Issue (5): 541-551.doi: 10.7657/XJPG20240505

• OIL AND GAS EXPLORATION • Previous Articles     Next Articles

Genesis and Identification of Low Resistivity of Oil Layers in Badaowan Formation on Southern Slope of Zhongguai Bulge, Junggar Basin

LI Fengling1a(), FANG Xinxin2(), ZHANG Zhen1b, MA Sijie1c, LIU Rongjun1d   

  1. 1. PetroChina Xinjiang Oilfield Company, a.Oilfield Technology Service Company; b.Hongshan Oilfield LLC; c.Heavy Oil Development Company; d.Research Institute of Exploration and Development; Karamay, Xinjiang 834000, China
    2. College of Civil Engineering and Architecture, Quzhou University, Quzhou, Zhejiang 324000, China
  • Received:2023-07-20 Revised:2023-11-01 Online:2024-10-01 Published:2024-10-09

Abstract:

Compared to other low-resistivity oil layers, the low-resistivity oil layers in the Lower Jurassic Badaowan formation on the southern slope of the Zhongguai bulge in the Junggar basin are characterized by early hydrocarbon accumulation, deep burial, large grain size, and low mud content, showing a unique low-resistivity genesis. Based on a comprehensive analysis on the genetic mechanisms of typical low-resistivity oil layers globally, together with the data of drilling, logging, well testing, and core analysis in the study area, the main controlling factors of the low-resistivity oil layers in the Badaowan formation were investigated from various perspectives including tectonics, sedimentation, diagenesis, reservoir characteristics, and hydrocarbon accumulation conditions. It is found that low resistivity of the oil layers in the study area is jointly controlled by macroscopic and microscopic factors. In a macroscopic setting with low tectonic amplitude and weak hydrodynamic sedimentation, low oil-water differentiation degree, high formation water salinity, and low tuff debris content are the main controlling factors for low resistivity, while low saturation of bound water is a secondary controlling factor. Accordingly, a chart illustrating the relationship between formation resistivity and oil/gas indicator coefficient was established, which matches the formation/production testing data in the study area by 92.9%. The study results provide a basis for identifying low-resistivity oil layers in the Badaowan formation on the southern slope of the Zhongguai bulge.

Key words: Junggar basin, Zhongguai bulge, Badaowan formation, low-resistivity oil layer, genetic mechanism, main controlling factor, oil layer identification

CLC Number: