A treatment method for improving the water absorption performance of a water injection well profile

Abstract

The invention provides a treatment method for improving the water absorption performance of the water injection well profile, which combines the profile control with the on-line acidification technology, the dominant channel is completely or partially blocked by the profile control, and then the SM environmental protection acid is online. Acidizing and transforming the low-permeability layer finally improved the profile of the water injection well and absorbed water evenly; this technology does not require the pipe string to be pulled up and down during the construction process, and the construction process is simple, which greatly saves the construction period, reduces the construction strength, and reduces the The cost investment is high, and the environmental protection is strong, and it has a good application prospect.

Description

technical field [0001] The invention belongs to the technical field of oilfield water injection development, and particularly relates to a treatment method for improving the water absorption performance of a water injection well profile. Background technique [0002] At present, in the process of water injection development in major oilfields in China, a large number of water injection wells have problems of uneven water absorption between layers and layers, resulting in uneven water flooding in plane and profile. The main problems at the site are as follows: (1 ) The development method of co-injection of vertical wells is adopted for reservoirs with extremely thick layers and thin interlayers. For oil reservoirs with many layers and small interlayers, conventional sub-injection technology cannot effectively stratify. (2) Special wellbore conditions such as casing deformation, damage, sand production, scaling, etc., will make it difficult to run and unseal the conventional m...

AI Technical Summary

Problems solved by technology

[0002] At present, in the process of water injection development in major oilfields in China, a large number of water injection wells have successively encountered problems of uneven water absorption between layers and within layers, resulting in prominent contradictions of uneven water flooding in the plane and section. The main problems in the field are as follows: (1 ) The reservoirs with extremely thick layers and thin interbeds adopt the development method of vertical well combined injection. For reservoirs with many layers and small interlayers, the conventional separate injection technology cannot effectively separate layers.

(2) Special wellbore conditions such as casing deformation, damage, sand production, scaling, etc. will make it difficult to run and unseal conventional mechanical injection strings, and there is a risk of overhaul

The above-mentioned reservoirs have been using the general water injection method for a long time. Due to the existence of fractures or dominant channels, the vertical contradiction is prominent, which seriously affects the improvement of water driving utilization.

For the treatment of this dominant channel, technologies such as chemical profile control and mechanical pipe string injection are usually used, which have problems such as large construction labor and high construction costs.

For the transformation of low-permeability layers, the currently commonly used temporary plugging acidification technology can acidify and transform low-permeability layers to improve injection capacity, but it cannot do long-term plugging of the whole or part of the high-permeability layers with dominant channels, and finally achieves Less than the purpose of uniform water flooding