Abstract

At present, the effect of different development patterns of interlayer like the length and the longitudinal position of interlayer on thermal recovery modes such as steam stimulation (CSS) and steam flooding (SF) is still a qualitative understanding, and there is no systematic study yet. Therefore, it is difficult to control the thermal production of thick oil reservoirs according to different interlayer patterns. In order to quantitatively analyze the influence of interlayer distribution pattern on steam huff and puff and steam flooding of horizontal wells in thick heavy oil reservoir, a numerical simulation model was established based on typical parameters of LD21 heavy oil reservoir in Bohai in China. Through comparison and research on the different modes of development longitudinal position, development length and development scale in non-permeable interlayer and semi-permeable interlayer. The influence of interlayer on the expansion law of steam chamber and ultimate oil recovery degree during steam huff and puff and steam flooding, and the main controlling factors of interlayer influencing oil recovery were obtained. The research results can be used for reference to optimize the location of thermal wells in thick heavy oil reservoir and reduce the influence of interlayer on thermal production effect of horizontal wells.

Key words: Heavy oil reservoir; interlayer; steam huff and puff; steam flooding; recovery.