Progress in pilot testing of microbial-enhanced oil recovery in the Daqing oilfield of north China

•Microbial-enhanced oil recovery technology has been used for oil recovery.•Application requirements and suitable reservoir conditions of the field tests are discussed.•The information can be basis for pilot tests for microbial-enhanced oil recovery.

Microbial-enhanced oil recovery (MEOR) is a biotechnology that utilizes biogas, biosurfactants, and biopolymers produced by, and degradation by subsurface fermentation process of microorganisms for enhancing oil production from substratum reservoir. In this report, we describe the progress made in pilot testing of MEOR in the Daqing oilfield of north China in recent decades and analyze suitable reservoir conditions and application requirements. By the end of 2012, cumulative oil increments reached 1.2 × 105 t using MEOR in the Daqing oilfield; of the oil produced, 518 wells of single-well microbial huff-and-puff yielded a cumulative incremental oil production of 6.3 × 104 t, and 10 projects with 45 well patterns adopted microbial flooding and profile modification to achieve a cumulative incremental oil production of 5.7 × 104 t. Thus, MEOR has proven to be an effective technique for routine operations in enhanced oil production in oil fields.