Research on Steam Injection Technology for Multi-Layer Heavy Oil Reservoir

Shengli heavy oil is mainly developed by steam huff and puff. The reservoir has serious sand production. Sand control in the pipe is common, and the inner diameter is small. Affected by factors such as heterogeneity and steam overlap, the multi-round huff and puff reservoirs are unevenly utilized and the development effect becomes worse. The conventional steam injection tool for separating layers has a large size. In this study, the process string of layered steam injection (selective layer steam injection) in sand control pipe is optimized and designed. The key tools of selective layer steam injection are matched. The influence of different steam injection processes on steam absorption law is compared through visual experiments. The parameters of selective layer steam injection are quantified by numerical simulation method, which guides the field applications. The research shows that compared with the general steam injection, the wellhead steam injection pressure of the selected layer steam injection is increased by 1.4% (0.25 MPa), and the line speed is increased from 4.6 m/s to 11.07 m/s. The engineering risk is low. In the process of general steam injection, the steam overlap is serious, the steam absorption of the top reservoir is larger, accounting for more than 60%. With the steam injection point moves down, the steam absorption of the bottom reservoir can increase more than 70%. The thermal efficiency of steam injection can increase from 58% to 67%. A huff and puff well in Shengli Oilfield adopts the layer selection steam injection technology to turn the cycle. The cumulative oil production is 746t. Compared with the previous cycle, the oil production increases by 145t. It shows that the development effect is effectively improved. The research results can provide reference and guidance for the development of similar heavy oil thermal recovery at home and abroad.