稠油油藏水平井热采吞吐产能预测新模型

针对普通稠油油藏水平井热采吞吐产能预测缺少合适计算模型的现状,通过建立加热区和未加热区的复合流动模型,考虑加热区和未加热区原油黏度的差异,研究了水平井单井热采吞吐产能预测的解析模型,推导了水平井热采吞吐相对于冷采的产能增产倍数计算公式。研究表明,增产倍数主要受加热半径、油层厚度和水平段长度等因素影响。以渤海N油田热采水平井典型数据为基础建立机理模型,通过数值模拟得到不同吞吐轮次的加热半径,在此基础上,利用新模型计算了不同吞吐轮次的产能增产倍数,预测第一轮吞吐的增产倍数为1.6倍,该值与渤海N油田10口热采吞吐水平井第一轮吞吐效果评价结果吻合程度较高。

Model for Capacity Forecasting of Thermal Soaking Recovery in Horizontal Wells in Heavy Oil Reservoirs

To address the lack of a suitable calculation model for productivity prediction of thermal soaking recovery in horizontal wells in conventional heavy oil reservoirs, by establishing composite geological model including heating zone and unheated zone and considering the difference of crude oil viscosity between the heating and unheated zones, an analytical model describing the production capacity of thermal soaking recovery in a single horizontal well was determined. Further, an equation for calculating the productivity increase of thermal soaking recovery with respect to cold recovery was proposed. The results show that the productivity multiple is mainly affected by factors such as the heating radius, oil layer thickness, and horizontal section length. Based on typical thermal recovery data in horizontal wells in the Bohai N oilfield, a mechanistic model was established. The heating radius of different soaking cycles was obtained by numerical simulation. On this basis, the increase of production capacity in different soaking cycles was calculated by the new model. It is predicted that the productivity increase of the first soaking cycle was 1.6 times, which was in good agreement with the evaluation results of the first thermal soaking cycle in the ten thermal soaking recovery horizontal wells at the Bohai N Oilfield.