Bioturbation enhanced petrophysical properties in the Ordovician carbonate reservoir of the Tahe oilfield,Tarim Basin,NW China  

作　　者：Yong-Bin Niu Meng-Yuan Cheng Li-Jun Zhang Jian-Hua Zhong Sheng-Xin Liu Duan Wei Zi-Lu Xu Pei-Jun Wang 

机构地区：[1]Key Laboratory of Biogenic Traces and Sedimentary Minerals of Henan Province,Jiaozuo 454003,Henan Province,China [2]Collaborative Innovation Center of Coalbed Methane and Shale Gas for Central Plains Economic Region,Henan Polytechnic University,Jiaozuo 454003,Henan Province,China [3]School of Geoscience,China University of Petroleum(East China),Qingdao 266580,Shandong Province,China [4]Institute of Geomechanics,Chinese Academy of Geological Sciences,Beijing 100081,China [5]School of Energy Resource,China University of Geosciences(Beijing),Beijing 100083,China [6]Development Affairs of Tarim Oilfield,PetroChina,Korla 841000,Xinjiang Uygur Autonomous Region,China

出　　处：《Journal of Palaeogeography》2022年第1期31-51,共21页古地理学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Grants No.41472104 to YBN).The property characterization and interpretation of controlling factor and restriction mechanism of those ichnofabrics enhanced reservoir capacity in marine carbonate rocks;Project supported by National Natural Science Foundation of China(Grants No.41102076 to YBN).Ichnofabrics and their reservoir modification effecs in the carbonate rocks from the Ordovician Majiagou Formation,Northwest Henan Province,China;Project supported by Natural Science Foundation of Henan Province,China(Grants Nos.202300410185to YBN,and 212300410349 to LJZ);Project supported by The Science and Technology Major Project of Shanxi Province,China(Grant No.20181101013-1);the Program for Innovative Research Team(in Science and Technology)in Universities of Henan Province,China(Grant No.21IRTSTHN007);the Program for Innovative Research Team(in Science and Technology)of Henan Polytechnic University(Grants Nos.T2022-5 and T2020-4);The Funddamental Research Funds for the Universities of Henan Province(Grant No.NSFRF200340to LJZ)。

摘　　要：Bioturbation plays an important role in enhancing the reservoir capacity of tight reservoirs.This study aims to understand the alteration mechanism and effects of bioturbation on oil and gas reservoirs,to clarify the key control factors and constraints influencing the production of bioturbation.The petrophysical characteristics of bioturbation and host sediments in carbonate rocks,such as mineral composition,pore spaces,porosity and permeability,were studied based on the detailed observation and description of the Ordovician cores from the Tahe oilfield.The effect of bioturbation on petrophysical properties of carbonate rocks were carefully analyzed.The results show:(1)Two types of bioturbation,Thalassinoides-like burrows and Planolites-like burrows,mainly occur in the Ordovician cores of the Tahe oilfield,ranging from the Lower-Middle Ordovician Yingshan Formation to the Middle Ordovician Yijianfang Formation.The burrow-fills are mainly composed of dolomite with subhedral and euhedral crystals.The host sediments mainly consist of micrite.(2)The pores in the host sediments are poorly developed and are incapable of forming effective reservoir spaces.However,well-developed intercrystalline pores among dolomites and microfractures in bioturbated sediments with better connectivity can form effective pore spaces.The results of porosity and permeability show that the host sediments without bioturbation are characterized by poor porosity and permeability.However,with the increase of bioturbation intensity,the porosity of the bioturbated sediments firstly increases and then decreases,whereas the permeability increases all the time.(3)Multiple burrows overprinted in the Ordovician carbonate rocks,forming a large-scale bioturbated carbonate rocks with lateral continuity and vertical connectivity,due to the suitable sedimentary setting,ecological conditions,favorable spatiotemporal sediment matching,and abundant organism-substrate interaction.Subsequently,diagenesis(particularly dolomitization and dissolution)has played a p

关 键 词：BIOTURBATION Carbonate reservoir DIAGENESIS ORDOVICIAN Tahe oilfield Tarim Basin 

分 类 号：P618.13[天文地球—矿床学]