摘要：The SAGD preheating stage is designed to establish inter-well hydraulic and thermal communication so as to create a steady steam chamber. Upon preheating, the previously immobile bitumen undergoes a change from solid to fluid phase due to thermal stimulation. The oil sand reservoir was divided into a rheological fusion zone and a solid zone, of which the mechanical and thermal properties differ dramatically. The modified Drucker-Prager plasticity were adopted to depict the mechanical behavior of both zones, using constitutive parameters that are temperature and phase dependent. It was discovered that (1) the bitumen in the reservoir near the well pairs will have changed from an immobile solid/semisolid to fluid state at the end of circulation. The temperature propagation speed is very fast in the fusion zone, but shows a slow tendency in the solid zone; (2) The deformation upon preheating is not only determined by temperature-induced mechanical properties, but also by the reservoir geometry such as the positions of the well pairs, the existence of mudstone cap/base rock. A high temperature always means a higher settlement. The temperature of the zone near the well pairs is higher than far zone, so their thermal properties such as elastic modulus deteriorates a lot, which leads to a larger stress release and framework deformation. (3) The stress in horizontal direction in the region close to the well pairs is larger than the far region. The horizontal stress on the wellbore is the largest in tension. Two obvious zones exist in the upper and lower sides where the horizontal stress is in compression, and its magnitude is about three times of the tensile stress on the wellbore. Similar phenomenon can also be found in the analysis for the vertical stress. The reservoir temperature and deformation predicted in this study can provide a guidance for the design of steam circulation for preheating SAGD wells.
Copyright © 2018 ARMA, American Rock Mechanics Association.

发表日期：2018-01-01

期刊分区（SCI为中科院分区）：无

收录情况：国际学术会议论文集

发表期刊名称：U.S. Rock Mech./Geomech. Symp.

通讯作者：高彦芳

第一作者：陈勉,林伯韬,金衍,刘兴云,赫文豪

论文类型：会议论文

论文概要：高彦芳,陈勉,林伯韬,金衍,刘兴云,赫文豪，Modeling of reservoir deformation upon preheating in SAGD wells considering phase change of bitumen，U.S. Rock Mech./Geomech. Symp.，2018，

论文题目：Modeling of reservoir deformation upon preheating in SAGD wells considering phase change of bitumen