Research And Application Of SAGD Technology Reservoir Engineering Optimization For Shallow Super Heavy Oil Double Horizontal Wells

SAGD (Steam Assisted Gravity Drainage) technology is an innovation exploitation of ultra-heavy oil reservoirs, which is used for ultra-heavy oil reservoir, making satisfactory results in the mining index and economic benefits. The article is based on the super heavy oil reservoirs of the Windy City Oil Field, on the basis of the system analysis of SAGD development instance, focusing on the adaptability of the reservoir geological parameters of SAGD development, establishing the screening criteria for shallow super heavy oil SAGD, and proposing a design concept of key parameters on SAGD steam chamber and expanding the fluid discharge; three-dimensional physical simulation tool is used to describe the SAGD steam chamber growth and yield increase in the intrinsic link between stability and decreasing deepen the shallow super heavy double horizontal wells SAGD extraction mechanism; the mezzanine description as the core and the fine three-dimensional reservoir architecture geological model, using numerical simulation techniques of thermal recovery to make reservoir engineering research and establish technology policy formulation suitable for shallow super heavy double horizontal well SAGD characteristics; under the Heavily32-well area, re-37well area SAGD pilot practice, a three (the temperature field, pressure field, the saturation field) is developed by being monitored as a means, the Sub-cool control as the core control strategy, injection well uniformly heat connectivity, the horizontal segment of uniformity to be used of technology critical to the regulation of production and expansion of the vapor chamber.This article is of large theoretical difficulty and deepth, results of the research are as follows.(1) Reservoir burial depth, temperature and pressure, the continuous oil layer thickness, vertical permeability and horizontal permeability ratio, the interlayer distribution, the viscosity of crude oil and reservoir geology parameters determine the adaptability of SAGD development; steam quality, steam injection speed, the pressure of the steam injection, liquid discharge capacity of the production wells, horizontal well length, injection and production wells from the reservoir engineering parameters such as SAGD steam chamber expansion and fluid discharge.(2) The three processes of production increase, stability and decreasing of pairs of horizontal wells on SAGD correspond to rise in the steam chamber, expansion, decline in three stages, and the contribution of oil production is mainly in the expansion phase, vapor chamber.(3) Establish the generous internal dissection prediction model of the beach bar according to the heart of the braided river, combined with dense well data to forecast laminated lateral extent of the SAGD pilot test area three-dimensional conformation distribution model based on outcrop measurements. Studies have shown that in the central part of dissection of braided river heart beach bar near the level of edges sandwich tilt mind beach bar edge and the center of the physical properties of laminated developmental scale, the center of digenetic mezzanine development of large-scale. (4) Numerical simulation of thermal recovery software is used for optimizing the key design parameters on the shallow super heavy horizontal well SAGD, cyclic warm-up of key parameters and key parameters of the production stage, the formation of a full reservoir engineering research methods, developed a mining technology policy.(5) By study of the Windy City oilfield SAGD pilot test area, the formation of a different column under the conditions of pulsed throughput and continuous steam injection cycle warm-up to optimize the control technology is explored, a turn SAGD timing criteria. Established three thermal connectivity mode the SAGD the Nagai segments connected at one end connectivity and multi-stage steam channeling, etc., and sub-cool control, corresponding to the injection and cross-injection and work system are developed. To improve the inter-well connectivity, the level of section effective the use of the degree as the primary task of the SAGD production stage should be raised, and on this basis, production pressure is reduced differently between the injection-production well, giving full play to the role of gravity drainage; Sub-cool range, inhibit the production wellbore easy flash; analysis of reservoir heterogeneity, column structure, and injection of the impact parameter expansion of the steam chamber to determine the impact the main controlling factors of the development of SAGD steam chamber, the development of the steam chamber development of regulatory strategies.(6) Analyze on the variation of the pressure difference between injection and production wells and mining injection, and make research on SAGD stages of segmentation and parameter optimization of injection and SAGD start-up phase and production phase is subdivided into uniform pressure cycle warm-up, balanced pressurized circulating Preheat the smooth transition of the early turn SAGD, the five stages of SAGD production of high-pressure production, SAGD production and stable production.Through the above research, the formation of a shallow and ultra-heavy double horizontal well SAGD reservoir engineering optimization, production process in a steam chamber, and the vapor-liquid interface control technology are designed, which have achieved a better effect in practice. The realization of the Windy City super heavy oil cost-effective development is of great significance.