Microbial assisted waterflood effectively increases production from a mature Carpathian oil field: Project results and analysis of economic efficiency at eighty months

摘要

This paper relates to the possibilities of applying Microbial Assisted Waterflood (MAW) technology in mature Carpathian oil fields. The geological structure of the Polish Carpathian Foothills is summarized, and a rational is given for continued use of microbial oil recovery technology in Polish Foreland reservoirs. Additionally, a recommendation is made to investigate the use of microbial oil recovery methods for other Carpathian reservoirs throughout the region where appropriate conditions exist. In support of this rational, the results from 80 months of an active MAW project at the Plawowice oil field are presented. Results of laboratory tests simulating the microbial flooding process at Plawowice have been presented earlier. From the beginning, the project was designed to economically improve the recovery factor (RF) from this depleted Carpathian Foreland reservoir. Phase I field work at Plawowice began in September, 2011. The initial bio-preparation was produced by INiG and delivered to the Plawowice oilfield. Once on site, it was further amplified in volume and then injected into the P1-311 injector in one large slug. Phase II in September, 2014 is marked by microbial re-treatment and project expansion. In June, 2017 the project moved into Phase III and as of March, 2019 it is halfway into the 8th year of continuous operation. Proper design and implementation of MAW technology at Plawowice has proven capable of increasing production rates from all three oil wells currently involved in the MAW project. Production from the P1-52, P1-159 and P1-111 oil wells all show significant increases in production substantially above their production rates before microbial treatment, with average values of these increments being 147%, 39% and 112% respectively. An assessment is made of the overall economic efficiency of the Project, concluding that an extension of the productive life of all project wells was achieved by phase III of the project.