Heavy oil thermal recovery fleeing proof agent

Abstract

The invention discloses a heavy oil thermal recovery fleeing proof agent comprising the following raw components by weight percent: sodium silicate 10-30%, ethyl acetate 0.5-3%, ammonium chloride 0.3-1.3%, aluminium citrate 0.005-0.015%, EDTA or EDTA salt 0.01-0 .03%, and the balance of water. The gelatinization time of the fleeing proof agent is 4-12 h. The gelatinized fleeing proof agent can resist steam with a temperature of 300 DEG C, can be used together with a suspended particle type fleeing proof agent, is used for performing deep fleeing prevent of a thermal recovery well with serious steam fleeing, and can enhance the fleeing proof effect. The fleeing proof agent can particularly be used for a heavy oil thermal-recovery sand-prevention well and can directly conduct fleeing prevention in the presence of a sand prevention layer or a sand prevention tool, thereby reducing the construction cost and achieving good effect.

Description

technical field [0001] The invention relates to a sealing agent for heavy oil thermal recovery, which belongs to the technical field of petroleum exploitation. Background technique [0002] Heavy oil is a kind of oil with high viscosity and poor fluidity, which is difficult to extract, and the viscosity needs to be reduced to facilitate extraction. Thermal recovery of heavy oil is the main technical means of heavy oil development. Heavy oil thermal recovery technologies mainly include steam huff and puff, steam flooding, cluster directional wells and horizontal wells, burning oil layers and other supporting technologies for heavy oil thermal recovery. Steam huff and puff recovery of heavy oil is a relatively simple and mature steam injection recovery technology. It is still widely used in Venezuela, the United States and Canada. There are also quite a few heavy oil reservoirs in my country's oilfields, such as Shengli, Henan, Liaohe, and Karamay. The method of extraction (he...

AI Technical Summary

Problems solved by technology

[0004] 1. It can only be used in steam channeling wells without sand control measures, and cannot be used in steam channeling wells after sand control measures are taken, because there are sand control layers or sand control tools in the sand control wells, and the particle size of the granular sealing agent makes it impossible to penetrate Pass through the sand control layer or sand control tools into the steam channel to block the steam channeling

[0005] 2. The squeeze injection pressure is high during construction, and the suspended particle sealing agent cannot be injected into the deep part of the formation in large doses, and the sealing effect on the deep part of the formation is poor.

[0006] Chinese patent application number: 200410029654.3 discloses a solution-type plugging agent, which is mainly used for profile control and water plugging of oil wells. Although the plugging agent can enter deep formations through sand control layers or sand control tools, it cannot withstand 200-300 ℃ high-temperature steam, so it cannot be applied in thermal recovery of heavy oil