Vertical Well Assisted SAGD Dilation and Coupled Numerical Simulation of Geomechanics and Thermal Recovery

doi:10.3969/j.issn.1006-6535.2021.03.012

Abstract

Abstract: In order to solve the problem of uneven production in horizontal interval after the start of SAGD dilation of dual horizontal wells in heterogeneous reservoir, a new composite dilation technology of vertical well assisted SAGD dilation in horizontal well was proposed from two aspects of improving seepage conditions and optimizing driving mechanism. By coupling the geomechanical finite element method with the numerical simulation model of thermal recovery in oil reservoir, the changes of physical parameters and fluid flow behavior of the geomechanical dilation reservoir of loose sandstone were analyzed, and the development effect of thermal recovery with steam injection after dilation by the new technology was predicted. The study results showed that the vertical well assisted SAGD dilation should be conducted in the order of horizontal well first and vertical well later, so as to prevent local channeling in the dilation position caused by vertical well dilation first, which was conducive to the formation of uniform composite dilation zone; the width of dilation zone of vertical well was sensitive to the angle between horizontal well track and in-situ stress direction, and the width of dilation zone was the largest when the horizontal well track was parallel to the maximum horizontal stress; whether vertical well connected to the dilation zone of horizontal well was not directly related to the angle between horizontal well track and in-situ stress direction; the greater the distance between the vertical well and the SAGD horizontal well, the more difficult it was to connect the dilation zone. Compared with the traditional SAGD technology, after the vertical well assisted dilation, the gravity drainage of the SAGD horizontal well and the steam huff and puff of vertical well could work together, and the effect of increasing production was significant. The study results can provide guidance for the on-site implementation of SAGD dilation.

Key words: vertical well assisted, SAGD dilation, geomechanics, finite element method, numerical simulation of thermal recovery, coupling, Fengcheng Oilfield

CLC Number:

TE345

Zhao Rui, Sang Linxiang, Chen Lunjun, Xu Bin, Luo Chihui, Meng Xiangbing. Vertical Well Assisted SAGD Dilation and Coupled Numerical Simulation of Geomechanics and Thermal Recovery[J]. Special Oil & Gas Reservoirs, 2021, 28(3): 81-86.

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