Electric Heating Mechanism and Operating Parameter Optimization in the Expansion Stage of SAGD Steam Chamber

doi:10.3969/j.issn.1006-6535.2022.03.018

Abstract

Abstract: To further improve the productivity of the horizontal intervals in SAGD well cluster that has entered the steam chamber expansion stage in Fengcheng Oilfield, an integrated numerical model of electric heating-assisted SAGD was established with typical reservoir parameters to study the seepage characteristics of downhole electric heating and optimize the design of operating parameters. The results showed that, downhole electric heating performed in the SAGD expansion stage had four important mechanisms: fixed-point heating, promotion of steam chamber development, fixed-point oil drainage, and improvement of effective permeability in low-permeability intervals; the reasonable steam injection rate was 158-171 m³/d, the steam chamber operating pressure was 4.9-5.4 MPa, the pressure difference between injection and production wells was 0.4-0.5 MPa, and the inter-well pressure difference between adjacent well clusters was less than 0.5 MPa; the reasonable electric heating duration was 2.0-3.0 years, the maximum surface temperature of the electric heater was 250 ℃, and the power was 800-1 000 W/m; the productivity of horizontal interval was increased from 67% to 100% after the typical well cluster was electrically heated for 3.0a, the daily oil production was increased by 2-4 m³/d,Accamulative oil-steam ratio in creased from 0.15 to 0.24, and the final recovery efficiency reached 51.3%, an increase of 8.1 percentage points. The study results can be used as a guidance for improving the development effect of SAGD.

Key words: electric heating, SAGD, steam chamber, daily oil production, oil-steam ratio, recovery efficiency, Fengcheng Oilfield

CLC Number:

TE357

Ding Chao, Yang Zhaochen, Wu Yongbin, Wang Li, Yang Haozhe, Wang Chao. Electric Heating Mechanism and Operating Parameter Optimization in the Expansion Stage of SAGD Steam Chamber[J]. Special Oil & Gas Reservoirs, 2022, 29(3): 124-130.

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