A Coalbed Gas Well Open Hole Well Completion Technology

Abstract

The invention relates to the coal bed gas mining technology and provides a coal bed gas well open hole well completion technology to solve the technical problem that the existing well completion technology pollutes the coal bed. The coal bed gas well open hole well completion technology comprises the following steps of (1) drilling through a first drill, utilizing the first drill to firstly drill an opening hole to form into a first opening hole, lowering a first surface layer casing pipe to the bottom of the first opening hole and cementing the well through cement; (2) drilling through a second drill, enabling the second drill to drill, finishing drilling when the second drill drills to 50.00m below a coal bed section base plate, lowering the same diameter casing pipe into the non-coal-bed layer, lowering a screen pipe into a coal bed section and continuously filling quartz sand to be above the coal bed top plate; (3) hole sweeping drilling, drilling the screen pipe section through a third drill, rinsing quartz sand filled inside the hole and using clean water from the beginning of the hole sweeping to finishing of the hole punching. The coal bed gas well open hole well completion technology guarantees not cementing the well at the coal bed section and accordingly reducing coal bed pollution, meanwhile being large in internal diameter and satisfying construction conditions of follow-up hydraulic fracturing and the like and the follow-up pump inspection work.

Description

technical field [0001] The invention relates to a coal bed gas mining technology, in particular to a coal bed gas well open-hole well completion technology. Background technique [0002] Coalbed methane occurs in coal reservoirs and is extracted through desorption, diffusion, and seepage migration. Coalbed methane is easily blocked by fine particles during the seepage process, reducing the output of coalbed methane. Therefore, in the completion technology of coalbed methane wells, it is required to adopt a low-pollution method to reduce particle clogging, and to adopt a non-cemented (open hole) method for coal seam section completion. [0003] Conventional drilling and casing running cementing and completion processes are carried out in strict accordance with the bit gradation (from larger to smaller bit size) standards. In the conventional drilling process, CBM wells are conventionally cemented with casing, and this process cannot avoid the problem of coal seam pollution n...

AI Technical Summary

Problems solved by technology

[0004] In order to solve the technical problem of polluted coal seams existing in the existing well completion process, the present invention provides a coalbed gas well open hole well completion process

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