doi:10.16186/j.cnki.1673-9787.2020040106

Received:2020/04/30

Revised:2020/06/03

Published:2021/07/15

Geological characteristics and exploration significance of reservoir solid bitumenin the Lower Paleozoic-Middle Proterozoic in Ordos basin

HUANG Junping1,2,3, LIN Junfeng4, ZHANG Lei5, HE Wenxiang1,2, LI Xiangbo3, XU Yaohui1,2, WANG Yating3, ZHANG Guisong5, WANG Hongbo3, WANYAN Rong3

1.Key Laboratory of Exploration Technology for OH and Gas Research of Ministry of Education， Yangtze University， Wuhan  430100 ， Hubei， China;2.College of Resources and Environment， Yangtze University， Wuhan  430100 ， Hubei， China;3.Research Institute of Petroleum Exploration & Development-Northwest ，Petro China ， Lanzhou 730020 ， Gansn， China;4.School of Energy Science and Engineering， Henan Polytechnic University， Jiaozuo  454000 ， Henan， China;5.Exploration and Development Institute， Petro China Changqing Oilfield Company，Xi' an  710018 ， Shaanxi， China

Abstract:Through field survey and core observation， a large number of reservoir solid bitumen has been found in Lower Paleozoic-Middle Proterozoic in Ordos Basin， and the Cambrian reservoir solid bitumen was found for the first time. Based on the study of reservoir solid bitumen's content， optical characteristics， maturity， genesis and resource potential， a series of new understandings have been obtained. The results showed that the asphalt content of Ordovician ranged from 0. 15% to 2. 38% ， the highest content of Cambrian was 7.62% ， and that of Jixian county was 2.21%. On the plane， the asphalt content in the south of the basin was relatively high， and gradually decreased to the north. It was speculated that its source might be related to the marine source rocks of Lower Paleozoic -Middle Proterozoic in the south of the basin. Under the microscope， excepting for a few weak fluorescence， most of the reservoir solid asphalt samples almost had no fluorescence， and had a clear shape and boundary. According to the conversion of laser Raman correlation parameters， the equivalent vitrinite reflectance of reservoir solid asphalt was 2. 32% 〜2. 80% ， indicating that it has reached the over mature evolution stage. Based on the geological characteristics of reservoir solid bitumen， it was considered that the lower Paleozoic Middle Proterozoic reservoir solid bitumen was mainly pyrobitumen formed by crude oil cracking. With the formation of coke tar pitch， a large amount of crude oil cracking gas would be generated. It was estimated that the total amount of gas generation in Lower Paleozoic Middle Proterozoic paleo reservoir was about 1.207 × 10¹³~2.559 × 10¹³ m³. The discovery of a large number of solid bitumen in Lower Paleozoic and Middle Proterozoic reservoirs and the study of oil and gas characteristics provided an important scientific basis for the search for large oil and gas fields in the deep Ordos basin.

Key words:Ordos basin;Lower Paleozoic-Middle Proterozoic;reservoir solid bitumen;geological characteristics;exploration significance

 鄂尔多斯盆地下古生界_中元古界储层固体沥青地质特征及油气勘探意义_黄军平.pdf