Abstract:

As one of the offshore heavy oil thermal exploitation technology, the multi thermal fluid stimulation technology had been carried out in the development of heavy oil in Bohai oilfield. By the theoretical analysis and numerical simulation method, we reasonably characterized the mechanism of multi thermal fluid huff and puff, introduced the concept of coefficient of variation, and obtained the main factors affecting the effect of multiple rounds of throughput, which were the injection strength, shift opportunity, injection temperature, and periodic increasing rate. Based on the reservoir characteristics of the typical oil field, and with the evaluation index of the rate of cycle output and input, we got the sample data of different cumulative oil production and gas retention conditions, and regressed the optimum injection strength in multiple cycles of multi thermal fluid huff and puff wells. Then we corrected the optimization by using the main factors influencing the thermal recovery effect, drew the optimized version to obtain the reasonable injection parameters accurately and efficiently, and improved the thermal recovery effect of huff and puff in multiple rounds.

Key words: multi thermal fluid, huff and puff in multiple rounds, influencing factor, parameter optimization, development effect