Analysis of On-Site Development Effect and Optimization of Injection Production Parameters for Single Horizontal Well SAGD

Single horizontal well SAGD can effectively develop thin layer ultra heavy oil reservoirs with continuous oil layer thickness of 6–10 m, but the development law and operating parameters of the steam chamber are still unclear. The Z01 well area of Fengcheng Oilfield implemented a single SAGD well FHW01 in 2009, which has been in operation for 15 years. Through analysis of production performance and changes in wellbore pipe string, the optimal deployment well trajectory was obtained. A numerical modeling mechanism model for typical well groups was established, and the development stages of steam chambers and optimal injection production parameters were obtained through simulation of the entire life cycle. The results show that point A of the well trajectory should sink below point B, using insulated tubing with the horizontal section perpendicular to the structural direction; The startup mode is throughput and electric heating mode. The production stage is electric heating assisted SAGD, with steam injection pressure 0.5–1 MPa higher than the formation pressure. The steam injection method is continuous injection, and the steam injection speed gradually increases from 30 t/d to 50 t/d, with a maximum not exceeding 50t/d. The sub coke temperature should be between 5–15 ℃, and the final oil to steam ratio is 0.18, with a recovery rate of 42%. This provides important technical support for the utilization of ultra heavy oil and difficult to recover reserves in single horizontal well SAGD.