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Temporarily plugging/shielding protection agent and preparation method thereof

A protective agent and solvent technology, which is applied in the field of shielding temporary plugging protective agent and its preparation, can solve the problems of decreased reservoir permeability, poor physical properties of tight clastic rock reservoirs, and unsatisfactory effects, etc., and achieve high temporary plugging Plugging rate and permeability recovery rate, good reservoir protection effect, good temporary plugging effect

Active Publication Date: 2018-06-01
CHINA UNIV OF PETROLEUM (EAST CHINA) +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0002] Tight clastic rock reservoirs have the characteristics of poor reservoir physical properties, small pore throat radius, and low matrix permeability. Due to their particularity, fracturing measures are generally used for exploitation, and fracturing fluids are used as well-entry fluids for fracturing oil and gas fields. During the fracturing process, filtration will enter the reservoir, which will easily cause problems such as water lock, wettability reversal, clay swelling, dispersion and migration, etc., which will eventually lead to a decrease in reservoir permeability and even failure of fracturing
[0003] At present, in order to solve the problem of fracturing fluid damage to the reservoir, water-blocking agents, clay stabilizers, fluid loss control agents, etc. are generally added to reduce water-locking and clay swelling in a targeted manner, but the effect is not ideal
Although it is not necessary to accurately obtain the diameter and distribution of formation pore throats, because it is an elastomeric shielding agent, when the reservoir pores or external pressure are high, the shielding agent will be squeezed into the depth of the pore throats, causing pore blockage and damage Oil and gas reservoir

Method used

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  • Temporarily plugging/shielding protection agent and preparation method thereof
  • Temporarily plugging/shielding protection agent and preparation method thereof
  • Temporarily plugging/shielding protection agent and preparation method thereof

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0042] A shielding temporary blocking protective agent, prepared by the following method:

[0043] (1) Prepare a gelatin protective agent solution with a mass fraction of 2% at 40° C., keep it warm for later use;

[0044] (2) Weigh 0.15g of polyvinylpyrrolidone and 3g of ethyl cellulose, dissolve them in dichloromethane under an ice-water bath at a constant speed of 300r / min, and prepare ethyl cellulose containing porogen Organic solution, in this organic solution, the mass concentration of porogen and ethylcellulose is 4%;

[0045] (3) Take by weighing 3g of salicylic acid solid powder, slowly join in (2) in the ethylcellulose organic solution that contains porogen, continue constant speed stirring suspension emulsification, make S / O suspension system emulsion for subsequent use;

[0046] (4) At room temperature, increase the stirring speed to 400r / min, slowly add the S / O suspension system prepared in step (3) into the gelatin solution, keep the stirring speed constant, and ...

Embodiment 2

[0076] Change the amount of polyvinylpyrrolidone in Example 1 to 0.6g, and keep the other conditions unchanged, to prepare a surface-coated shielding temporary blocking protection agent.

[0077] The shielding temporary blocking protection agent prepared in this example was tested according to the gel breaking performance measurement in Example 1. The results are shown in Table 4.

[0078] Table 4 Results

[0079]

[0080] Compare the gel breaking time of the shielding temporary blocking agent prepared in this example with that of the shielding temporary blocking agent prepared in Example 1. The gel-breaking time can be shortened by increasing the porogenic dose, and the gel-breaking time can be adjusted by changing the porogenic dose.

Embodiment 3

[0082] A shielding temporary blocking protective agent, prepared by the following method:

[0083] (1) Prepare a polyvinyl alcohol protective agent solution with a mass fraction of 5% at 40° C., and keep it warm for subsequent use;

[0084] (2) Weigh 0.3g of polyvinylpyrrolidone and 3g of ethyl cellulose, dissolve them in dichloromethane under an ice-water bath at a constant speed of 300r / min, and prepare ethyl cellulose containing a porogen An organic solution, in which the mass concentration of porogen and ethyl cellulose is 3%;

[0085] (3) Weigh 1.5g salicylic acid solid powder, the median particle diameter is 10 μm, slowly join in (2) in the ethylcellulose organic solution that contains porogen, continue constant speed stirring suspension emulsification, obtained S / O suspension system emulsion is ready for use;

[0086] (4) At room temperature, increase the stirring speed to 400r / min, slowly add the S / O suspension system prepared in step (3) into the protective agent so...

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Abstract

The invention specifically relates to a temporarily plugging / shielding protection agent and a preparation method thereof, belonging to the field of temporary plugging agents for energy exploitation. The temporarily plugging / shielding protection agent is prepared by successively coating organic acid solid particles with ethyl cellulose, which is mixed with a pore-foaming agent, at first and then with a protective agent next. The temporarily plugging / shielding protection agent provided by the invention is applied to the development of oil and natural gas in tight clastic rock reservoirs, and ismainly used for reservoir protection during fracturing completion. The temporarily plugging / shielding protection agent is used in the process of fracturing to form a temporarily plugging / shielding zone under the action of pressure difference so as to reduce fracturing fluid loss and prevent fracturing fluids from entering strata; in a later phase, a coated material is slowly dissolved and releasedthrough micropores, which is beneficial for gel breaking and flowing back of fracturing fluids; after the coated material, i.e., a gel breaker, is dissolved and released, a flexible coating becomes ahollow flexible shell, so the flexible coating is not supportive and is thus peeled off from a temporarily plugged surface and discharged back together with the gel-broken fracturing fluid; and aftercompletion of construction, no residue is left in the strata, so reservoir damage is reduced.

Description

technical field [0001] The invention relates to the field of temporary plugging agents for mining energy, in particular to a shielding temporary plugging protection agent and a preparation method thereof. Background technique [0002] Tight clastic rock reservoirs have the characteristics of poor reservoir physical properties, small pore throat radius, and low matrix permeability. Due to their particularity, fracturing measures are generally used for exploitation, and fracturing fluids are used as well-entry fluids for fracturing oil and gas fields. During the fracturing process, filtration will enter the reservoir, which will easily cause problems such as water lock, wettability reversal, clay swelling, dispersion and migration, etc., which will eventually lead to a decrease in reservoir permeability and even failure of fracturing. [0003] At present, to solve the problem of fracturing fluid damage to the reservoir, water-blocking agents, clay stabilizers, fluid loss contr...

Claims

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Application Information

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Patent Type & Authority Applications(China)
IPC IPC(8): C09K8/516
CPCC09K8/516
Inventor 王增宝纪圆白英睿赵修太赵梦云尚校森李雪鹏陈桾泽陈安胜何海峰宋立阳
Owner CHINA UNIV OF PETROLEUM (EAST CHINA)
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