PMID- 32596575
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200928
IS  - 2470-1343 (Electronic)
IS  - 2470-1343 (Linking)
VI  - 5
IP  - 24
DP  - 2020 Jun 23
TI  - Plugging High-Permeability Zones of Oil Reservoirs by Microbially Mediated 
      Calcium Carbonate Precipitation.
PG  - 14376-14383
LID - 10.1021/acsomega.0c00902 [doi]
AB  - Simple plugging of the high-permeability "thief zones" of oil reservoirs is the 
      most plausible and also the most straightforwardly achievable approach to enhance 
      sweep efficiency and oil recovery. Sporosarcina pasteurii is a representative 
      microorganism with the ability to precipitate calcium carbonate (CaCO(3)) via 
      enzymatic hydrolysis of urea in the presence of calcium ions. Microbially induced 
      calcium carbonate precipitation (MICP) can cement and seal the granular and 
      fractured media and thus can be used as a potential microbial plugging agent for 
      the high-permeability zones of oil reservoirs. The following investigated the 
      microscopic characteristics of MICP plugging and its efficacy in permeability 
      reduction. The columns of near-spherical silica sand and angular silica sand with 
      three separate granularities (40/60, 60/80, and 80/120 mesh) were used as 
      artificial rock cores representing distinct pore sizes and pore characteristics 
      to investigate the efficacy and microprocess of MICP plugging with different 
      biotreatment periods. The results indicated that permeability is reduced 
      significantly after only short periods of biotreatment. After eight cycles of 
      MICP treatments, the permeability for each type of cores dropped by 54-90% of 
      individual initial permeabilities. The measured CaCO(3) content indicated that 
      the decreasing rate in permeability with the increasing CaCO(3) content 
      experiences three contrasting stages, namely, slow decline, speedy decline, and 
      plateauing. X-ray diffraction indicated that most of the generated CaCO(3) 
      crystals occur as vaterite with only a small amount of calcite. Imaging by 
      scanning electron microscopy further revealed the microprocess of MICP plugging. 
      Microorganisms first concentrate on the pore wall to secrete CaCO(3), forming a 
      thin and large uniform layer of CaCO(3). Then, some nucleation sites of CaCO(3) 
      crystals will experience further preferential growth, resulting in large, 
      dominant crystals that act as a plugging agent within the pore space. Compared to 
      extracellular polymeric substances, which are currently the primary microbial 
      plugging agent used to enhance sweep efficiency of oil reservoirs, bio-CaCO(3) 
      appears more effective in plugging in terms of its morphology, size, and growth 
      characteristics.
CI  - Copyright (c) 2020 American Chemical Society.
FAU - Song, Chenpeng
AU  - Song C
AD  - National Inland Waterway Regulation Engineering Research Center, Chongqing 
      Jiaotong University, Chongqing 400074, China.
AD  - Department of Energy and Mineral Engineering, EMS Energy Institute and G3 Center, 
      Pennsylvania State University, University Park, Pennsylvania 16802, United 
      States.
FAU - Chen, Yulong
AU  - Chen Y
AD  - School of Energy and Mining Engineering, China University of Mining and 
      Technology, Beijing 100083, China.
FAU - Wang, Jiehao
AU  - Wang J
AD  - Department of Energy and Mineral Engineering, EMS Energy Institute and G3 Center, 
      Pennsylvania State University, University Park, Pennsylvania 16802, United 
      States.
LA  - eng
PT  - Journal Article
DEP - 20200609
PL  - United States
TA  - ACS Omega
JT  - ACS omega
JID - 101691658
PMC - PMC7315417
COIS- The authors declare no competing financial interest.
EDAT- 2020/07/01 06:00
MHDA- 2020/07/01 06:01
PMCR- 2020/06/09
CRDT- 2020/06/30 06:00
PHST- 2020/02/28 00:00 [received]
PHST- 2020/05/29 00:00 [accepted]
PHST- 2020/06/30 06:00 [entrez]
PHST- 2020/07/01 06:00 [pubmed]
PHST- 2020/07/01 06:01 [medline]
PHST- 2020/06/09 00:00 [pmc-release]
AID - 10.1021/acsomega.0c00902 [doi]
PST - epublish
SO  - ACS Omega. 2020 Jun 9;5(24):14376-14383. doi: 10.1021/acsomega.0c00902. 
      eCollection 2020 Jun 23.