Slow blockage removing agent for oil well and blockage removing method

A plug-relieving agent and retarding technology, applied in the field of oil well plug-removing, retarding plug-removing agent, and plug-relieving agent, which can solve problems such as unfavorableness, damage to the rock skeleton of the reservoir, and increasing the depth of action of the plug-relieving agent.

Active Publication Date: 2016-01-20
CHINA PETROLEUM & CHEM CORP +1
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

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Problems solved by technology

However, hydrochloric acid and hydrofluoric acid are highly corrosive. When the two are used as the main body of the acid solution, the acid-rock reaction speed is too fast, whic...

Method used

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  • Slow blockage removing agent for oil well and blockage removing method

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Effect test

Embodiment 1

[0027] In this embodiment, the oil well retarding plugging agent is composed of pre-fluid, main body fluid and post-fluid according to the volume of 50m 3 、150m 3 and 50m 3 Composition; the pre-fluid and the post-fluid are composed of the following components in mass percentage: hydrochloric acid 8%, ammonium chloride 0.8%, citric acid 0.6%, AS-30.4%, SJ-210.6%, ethylene glycol butyl ether 0.4% %, the balance is water; the main liquid is composed of the following components in mass percentage: 5% glacial acetic acid, 3% fluoroboric acid, 1.2% ammonium chloride, 0.4% citric acid, 0.6% hydrolytic lock agent, 0.4% corrosion inhibitor, Ethylene glycol butyl ether 0.6%, the balance is water. The preparation method of each treatment solution is the same, that is, mixing each component and then stirring evenly.

[0028] The oil well plugging removal method comprises the following steps:

[0029] 1) For the HH37P15 well, the production string in the well was first lifted out, and ...

Embodiment 2

[0036]In this embodiment, the retarding plugging agent for oil well is composed of pre-fluid, main body fluid and post-fluid according to the volume of 42m 3 、126m 3 and 42m 3 Composition; the pre-fluid and the post-fluid are composed of the following components in mass percentage: hydrochloric acid 8%, ammonium chloride 1%, citric acid 0.5%, AS-30.5%, SJ-210.5%, ethylene glycol butyl ether 0.5% %, the balance is water; the main liquid is composed of the following components in mass percentage: 5% glacial acetic acid, 3% fluoroboric acid, 1% ammonium chloride, 0.5% citric acid, 0.5% hydrolytic lock agent, 0.5% corrosion inhibitor, Ethylene glycol butyl ether 0.5%, the balance is water. The preparation method of each treatment solution is the same, that is, mixing each component and then stirring evenly.

[0037] The oil well plugging removal method comprises the following steps:

[0038] 1) For Well HH37P23, the production pipe string in the well is first lifted out, and t...

Embodiment 3

[0045] In this embodiment, the oil well slow blockage removing agent is composed of pre-fluid, main body fluid and post-fluid according to the volume of 55m 3 、175m 3 and 55m 3 Composition; preflush consists of the following components in mass percentage: hydrochloric acid 8%, ammonium chloride 1.2%, citric acid 0.4%, AS-30.6%, SJ-210.4%, ethylene glycol butyl ether 0.6%, and the balance is Water; the main liquid is composed of the following components in mass percentage: 5% glacial acetic acid, 3% fluoroboric acid, 1% ammonium chloride, 0.5% citric acid, 0.5% hydroblocking agent, 0.5% corrosion inhibitor, butyl glycol ether 0.5%, the balance is water; the post liquid is composed of the following components in mass percentage: hydrochloric acid 8%, ammonium chloride 1%, citric acid 0.5%, AS-30.4%, SJ-210.4%, ethylene glycol butyl ether 0.6%, the balance is water. The preparation method of each treatment solution is the same, that is, mixing each component and then stirring ...

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Abstract

The invention discloses a slow blockage removing agent for an oil well and a blockage removing method, and belongs to the technical field of oil field exploitation. The slow blockage removing agent is prepared from prepad fluid, main fluid and post-pad fluid, the prepad fluid and the post-pad fluid both take hydrochloric acid as the main component of acid fluid for removing inorganic scale precipitation and dissolving reaction residues, and the main fluid takes glacial acetic acid and fluoboric acid as the main components of acid fluid for stabilizing clay mineral of a reservoir stratum, decreasomg the acid rock reaction speed, enlarging the blockage removing radius and increasing the blockage removing depth. For a fracturing production horizontal well, the treatment fluid is injected into the reservoir stratum in the former stage, the intermediate stage and the later stage, and liquid nitrogen is simultaneously injected, so that residual reaction fluid can be quickly drained after blockage removing construction is performed; pollution blockage near a well bore of the oil well can be effectively removed, the effective permeability near the well bore is increased, the individual-well producing rate is increased, damage caused by excessive acid corrosion to the rock framework of the reservoir stratum can be avoided, and therefore the reservoir stratum can be prevented from being subjected to secondary damage.

Description

technical field [0001] The invention relates to a plugging removal agent, in particular to a slow plugging removal agent used for removing blockage in the near-well zone of an oil well, and also relates to a plugging removal method for an oil well, which belongs to the technical field of oilfield exploitation. Background technique [0002] During the drilling process, the long-term contact between the drilling fluid and the reservoir will cause different degrees of damage to the reservoir, especially for horizontal wells that adopt fracturing and put into production, a large amount of fracturing fluid injected into the formation will inevitably have an adverse effect on the reservoir. The damage of fluid to the reservoir can lead to the decrease of oil phase permeability, the expansion of clay minerals in the reservoir, the migration and precipitation of particles, etc., which block the effective seepage channel of the reservoir and reduce the production of a single well. Th...

Claims

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Application Information

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IPC IPC(8): C09K8/524C09K8/528C09K8/68C09K8/74
CPCC09K8/524C09K8/528C09K8/68C09K8/74C09K2208/32
Inventor 董光唐万举李嘉瑞李国锋张永春王帆刘威蒋艳芳徐兵威
Owner CHINA PETROLEUM & CHEM CORP
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