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Preparation method and construction method of prefabricated fracturing displacement isolator

A construction technique and isolator technology, which is applied in the field of preparation of prefabricated fracturing displacement isolators, can solve problems such as viscous fingering and over-displacement, and achieve the effect of small well control risk, simple operation method, and convenient operation

Inactive Publication Date: 2019-06-28
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0006] The technical problem to be solved by the present invention is to provide a preparation method and construction technology of a prefabricated fracturing displacement isolator in view of the deficiencies in the above-mentioned prior art, so as to overcome the viscous fingering and excessive replacement problem

Method used

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  • Preparation method and construction method of prefabricated fracturing displacement isolator
  • Preparation method and construction method of prefabricated fracturing displacement isolator
  • Preparation method and construction method of prefabricated fracturing displacement isolator

Examples

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Effect test

Embodiment 1

[0055] A vertical well in the east area of ​​Sulige, Changqing was reformed by the mechanical packer single-seal fracturing process. The well depth of the first layer of the target layer was 2500m, and the Φ73.0mm tubing single-seal fracturing string was used to inject plant starch, polymer, The expansion agent and the curing agent are composed according to the mass ratio of 6.5:4:0.5:3, and the density (normal temperature): 1.01g / cm 3 , stir to obtain the raw material mixture and make a rubber stopper, the construction steps are as follows:

[0056] Step 1: Perforating the target layer of the gas well with pressure through the casing;

[0057] Step 2: According to the well depth, select the prefabricated fracturing replacement isolator that starts to dissolve after reaching the depth of the fracturing layer at 60-90°C for 2 hours, and preset the rubber plug at the wellhead;

[0058] Step 3: Complete the pumping in the stages of low replacement, setting, pre-fluid, and sand-c...

Embodiment 2

[0062] A vertical well in the south area of ​​Sulige, Changqing was refractured by mechanical packer staged fracturing technology. There were 2 target layers. Layer-by-layer fracturing reconstruction is carried out for each layer, and the composition of plant starch, polymer, expansion agent and curing agent is according to the mass ratio of 7.5:5:0.7:4, and the density (normal temperature): 1.21g / cm 3 , stir to obtain the raw material mixture and make a rubber stopper, the construction steps are as follows:

[0063] Step 1: Take out the perforating gun from the first layer and the second layer of the target layer of the perforated gas well through casing under pressure;

[0064] Step 2: According to the well depth, select one prefabricated fracturing replacement isolator that starts to dissolve after 4 hours at the depth of the fracturing layer at 90-120°C, and one prefabricated fracturing replacement isolator that starts to dissolve after 2 hours. The rubber plug is preset ...

Embodiment 3

[0071] A vertical well in the south area of ​​Sulige, Changqing was refractured by mechanical packer staged fracturing technology. There were 2 target layers. Layer-by-layer fracturing reconstruction is carried out on each layer, and the composition of plant starch, polymer, expansion agent and curing agent is in a mass ratio of 8:6:0.8:5, and the density (normal temperature): 1.3g / cm 3 , stir to obtain the raw material mixture and make a rubber stopper, the construction steps are as follows:

[0072] Step 1: Take out the perforating gun from the first layer and the second layer of the target layer of the perforated gas well through casing under pressure;

[0073] Step 2: According to the well depth, select one prefabricated fracturing replacement isolator that starts to dissolve after 4 hours at the depth of the fracturing layer at 90-120°C, and one prefabricated fracturing replacement isolator that starts to dissolve after 2 hours. The rubber plug is preset at the wellhead;...

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Abstract

The invention discloses a preparation method and construction method of a prefabricated fracturing displacement isolator. A polymer and plant starch are mixed evenly, and an expansion agent and a curing agent are added into the mixture of the polymer and the plant starch, stirred and mixed evenly to obtain a raw material mixture; then the raw material mixture is injected into a mold of a rubber plug, and the displacement isolator is obtained. Raw materials for preparation of the rubber plug are wide in source and easily obtained, the preparation method is simple and feasible, the operation method is simple, the cost is reduced while the efficiency is improved, and the viscous fingering and over-displacement problems caused by an existing gas field fracturing displacement fluid stage are solved on the basis that the operation difficulty of field construction is not increased.

Description

technical field [0001] The invention belongs to the technical field of low-permeability gas reservoir transformation, and in particular relates to a preparation method and construction technology of a prefabricated fracturing replacement isolator. Background technique [0002] Low-permeability oil and gas reservoirs, especially tight oil and gas reservoirs, require fracturing to improve single well production and stable production period. At present, vertical directional wells in low-permeability reservoirs mainly adopt mechanical packer staged fracturing technology, and the fracturing fluid system mainly adopts cross-linked guar gum fracturing fluid system. According to the role of different stages in fracturing, it can be divided into three types: pre-fluid, sand-carrying fluid and displacement fluid. The pre-fluid is generally a low-concentration base fluid, and its function is to open the formation and create cracks of a certain geometric size for the subsequent sand-ca...

Claims

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Application Information

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IPC IPC(8): E21B43/267C09K8/80
Inventor 郝瑞芬张燕明李宪文周长静问晓勇肖元相沈磊史华李红英李树生
Owner PETROCHINA CO LTD
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