Linking method for dual horizontal wells

Abstract

The invention discloses a linking method for dual horizontal wells and relates to the field of oil and gas exploitation. The linking method comprises steps of testing a steam injection horizontal well and a producing horizontal well, injecting a solvent to the steam injection horizontal well and the producing horizontal well, injecting water to the steam injection horizontal well via a shaft of the steam injection horizontal well, injecting water to the producing horizontal well via a shaft of the producing horizontal well, continuously injecting water to the steam injection horizontal well and the producing horizontal well respectively, improving water injection pressure of the steam injection horizontal well and the producing horizontal well, closing the steam injection horizontal well and the producing horizontal well and injecting gas to the steam injection horizontal well and the producing horizontal well respectively when a first preset condition is met to enable underwell water to flow back to the ground, and injecting equal-pressure steam to the steam injection horizontal well and the producing horizontal well to meet a second preset condition when the underwell water flows back to the ground. Link evenness of the dual horizontal wells can be effectively enhanced, linking time of the dual horizontal wells can be shortened and solvent consumption amount can be greatly reduced.

Description

technical field [0001] The invention relates to the field of oil and gas development, in particular to a method for connecting two horizontal wells. Background technique [0002] The SAGD development of shallow super heavy oil with dual horizontal wells has achieved success in Canada and has been applied commercially. Therefore, this development method has also gradually received attention in my country. During the start-up stage of SAGD, due to the low initial temperature of the reservoir and the high viscosity of crude oil, it is difficult to form an effective connection between the traditional dual horizontal wells with a well spacing of 5 meters. The vapor chamber also cannot be expanded, so it is important to establish effective fluid communication. In addition, the thermal communication between wells is also very important. The heavy oil heated at the upper part will lose heat during the slow seepage process to the lower production wells, resulting in a drop in temper...

AI Technical Summary

Problems solved by technology

During the start-up stage of SAGD, due to the low initial temperature of the reservoir and the high viscosity of crude oil, it is difficult to form an effective connection between the traditional dual horizontal wells with a well spacing of 5 meters. The vapor chamber also cannot be expanded, so it is important to establish effective fluid communication

In addition, the thermal communication between wells is also very important. The heavy oil heated at the upper part will lose heat during the slow seepage process to the lower production wells, resulting in a drop in temperature and an increase in viscosity, which will make it difficult for crude oil to flow between wells and prevent smooth oil drainage. process

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