Artificial lifting approach for fireflood of the Menggulin conglomerate heavy oil reservoir

To deal with the gas lock, pump stuck by sands and pipe corrosion of production wells in the Menggulin conglomerate oil reservoir under fireflood and improve the production time efficiency of wells and fireflood performance, the fireflood practice in China was reviewed, and the factors affecting artificial lifting were investigated in the context of fireflood. It was concluded that sucker rod pumps are still the most applicable artificial lifting approach. The pump barrel structure of the specialized sand-resistant pump was optimized. The matching clearance between the piston and pump barrel was 0.1 mm, and an independent channel was designed for flowing and settling of sands, with the sand-settling chamber annulus of 8 mm, both in attempt to facilitate sand control of formation sands. Theoretical and experimental analyses were integrated to determine the optimal structural configuration of the downhole separator: a pitch of 4 cm and a secondary settling section length of 20 cm, associated with the separation efficiency exceeding 85%. The anti-corrosion materials were optimized, and the BG90-30Cr was considered cost-effective for corrosion prevention. The field application suggested that the optimized artificial lifting pipe string delivers integrated functions of sand control, gas control and anti-corrosion. As of March 30, 2023, well M10-215 has been continuously and stably producing for 125 days under high gas-liquid ratio conditions. Compared with newly drilled and produced oil wells in the same block, the production time has been extended by more than 86 days, with a cumulative increase of 265 tons of oil. This provides technical support and guidance for the deep development of subsequent fire drive reservoirs.