Thermo-sensitive sand consolidation, channeling sealing and well completion integrated chemical system used for steam injection for thermal recovery

Abstract

The invention relates to a thermo-sensitive sand consolidation, channeling sealing and well completion integrated chemical system used for steam injection for thermal recovery. The chemical system is characterized in that it includes a low viscosity furfuryl alcohol prepolymer, a temperature selective curing agent, and resorcinol. The chemical system is chemically stable under oil reservoir temperature and wellbore temperature conditions. Thermal initiation after steam injection can be utilized to form high strength foam resin with cured resin as a continuous phase and gas as a dispersion phase, and a resin film is formed on a stratum sand surface. The stratum sand is cemented through a hydrogen bond, thus consolidating the stratum sand and plugging large channels. A single-fluid technique can be adopted for construction in a thermal recovery development process, and integration of sand consolidation and channeling sealing can be realized.

Description

technical field [0001] The invention relates to a chemical system for chemical sand cementing completion, chemical sand control and water sealing of oil and gas wells in the development of oil and gas fields, belonging to the field of oil reservoir exploitation. technical background [0002] Injecting high-temperature steam is one of the most effective methods to improve the production effect of heavy oil reservoirs. However, the erosion and thermal expansion of high-temperature steam damage the formation consolidation of heavy oil reservoirs, and sand particles are exported with oil flow, seriously affecting normal production. And with multiple rounds of huff and puff development, the problem of steam channeling has become more and more prominent, resulting in low thermal efficiency of steam, serious waste of energy consumption, and low recovery of heavy oil. very important. Among them, chemical sand consolidation is a kind of sand control completion method, which uses che...

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Problems solved by technology

Although the thermosetting resin plugging agent has strong plugging ability, long validity period and good high temperature resistance, it is limited by factors such as its non-selective plugging, cumbersome construction process, and poor controllability caused by the curing speed being very sensitive to temperature. Application in Development of Steam Thermal Recovery

[0004] Generally speaking, there are two main deficiencies in the existing technology. On the one hand, with the development of multiple rounds of huff and puff and steam flooding, higher requirements are put forward for its temperature resistance, thermal stability and plugging strength. Most of them have a short validity period or even can’t be used under high temperature in thermal recovery. On the other hand, the above-mentioned sand consolidation and plugging processes are carried out separately at present, and in order to prevent consolidation in the wellbore, it is necessary to use spacer fluid and external curing agent. There are problems such as complex construction technology and high risk factor of on-site construction

[0005] The main oilfields producing heavy oil in my country have gradually shifted to multiple rounds of steam huff and puff and steam flooding production stages, and the production temperature in the near wellbore area can be as high as 300 °C, and, with the continuous increase of development intensity, the sand production of huff and puff wells is becoming more and more serious, but conventional Resin is easily degraded at high temperature and loses its consolidation effect; at the same time, during steam injection of heavy oil, due to the heterogeneity of the reservoir and the huge difference between the mobility of steam and high-viscosity crude oil, steam gravity will occur. The vertical steam sweep efficiency is lower than 40% due to steam channeling such as overlapping and steam fingering, the oil-steam ratio becomes smaller, the oil production drops sharply, and the economic benefit is poor, which brings serious difficulties to the heavy oil production in the oil field

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