Main methods and evaluation on the efficiency of steam injection for heavy oil reservoirs——by taking Ed_33~(63) sublayer of block Jin 17 in Jinjia oilfield as an example

Ed3363 sublayer of block Jin17 in Jinjia oilfield is a heavy oil reservoir, which is developed with cyclic steam stimulation by horizontal wells. In recent years, the development problems such as the decrease of thermal recovery effect, low formation energy and the aggravation of steam channeling have become increasingly prominent. Meantime, affected by the high steam injection cost, the workload of steam stimulation has been reduced, and the thermal recovery mode has been limited. Therefore, in order to balance the contradiction between steam injection effect and economic benefit, the optimization of selecting well is carried out in this block. Through numerical simulation research and development dynamic analysis, the remaining oil and pressure distribution, formation deficit, periodic oil steam ratio and other indicators are used to screen cyclic wells with huff and puff, and the ineffective or low benefit wells are eliminated through economic benefit calculation. At the same time, in order to further improve the steam injection effect and control the operation cost, through optimizing the steam injection parameters, the reasonable steam injection intensity and the proportion of mixed injection between nitrogen and steam are studied. After the implementation in the field, the thermal recovery effect and economic benefit are good, which provides guiding significance for the efficiency of steam injection for Jinjia oilfield.