Chemical plugging agent for oil field workover

A workover and oilfield technology, applied in the field of chemical plugging agents for oilfield workover, can solve the problems of short plugging validity period, low plugging strength, and low pressure resistance level, and achieve long plugging validity period, large plugging radius, The effect of high compressive strength

Active Publication Date: 2019-01-22
CHINA PETROLEUM & CHEM CORP +1
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  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0005] The purpose of the present invention is to overcome the low pressure resistance level of the above-mentioned prior art, or the presence of some oil well plugging agents mainly composed of organic components, easy to age, short plugging validity period, poor fluidity, small treatment radius, and low plugging strength and other defects, a high-strength plugging agent was re-studied and applied, with a pressure resistance of more than 35MPa and a sealing radius of more than 2.5 meters

Method used

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  • Chemical plugging agent for oil field workover

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0019] Well H5-152 in Huzhuangji, Zhongyuan Oilfield, the well S 3 middle 2 , 1961.2-1972.3 meters, 5.5 meters / 3 layers, severe water flooding, according to the adjustment requirements of the well group to implement plugging of this layer. The on-site plugging agents are as follows by mass percentage: 65% superfine cement, 8% bentonite, 8% calcium oxide, 12% calcium carbonate, 5% asbestos wool, 0.5% carboxymethyl cellulose, 0.5% polynaphthalenesulfonic acid, Sulfomethyl tannin 1% solid phase mixing and stirring evenly. During construction, mix it with water at a ratio of 1:1.5 to make mortar, and inject it into the layer to be plugged. The treatment radius is 2.5m, and after 36 hours of curing, the drilling plug is tested to be qualified at 30MPa.

Embodiment 2

[0021] Well H96 in Huzhuangji, Zhongyuan Oilfield, the well S 3 middle 8 , 2306.5-2362.3 meters, 12 meters / 6 layers, severe water flooding, according to the adjustment requirements of the well group, the blockage will be implemented in this layer. The on-site plugging agents are as follows by mass percentage: ultrafine cement 70%, bentonite 6%, calcium oxide 6%, calcium carbonate 10%, asbestos wool 6%, carboxymethyl hydroxyethyl cellulose 0.7%, sulfonated melamine 0.7% resin and 0.6% sodium tannate are mixed and stirred evenly in solid phase. During construction, mix it with water at a ratio of 1:1.5 to make mortar, and inject it into the layer to be plugged. The treatment radius is 2.8m, and after 36 hours of curing, the drilling plug is tested to be qualified at 30MPa.

Embodiment 3

[0023] Well Qingzuji Q21-3 in Zhongyuan Oilfield, this well is a water well, and the water absorption profile shows that S 3 Down 4 , 1865.2-1902.3 m, 6.5 m / 2 layers, 100% water absorption, in order to improve the degree of production of other layers, it was decided to plug S 3 Down 4 . The on-site plugging agent by mass percentage is: 80% superfine cement, 3% bentonite, 4% calcium oxide, 6% calcium carbonate, 5% asbestos wool, 0.5% carboxymethyl cellulose, 0.5% sulfonated melamine resin , Sodium tannate 1% solid phase mixing and stirring evenly. During construction, mix it with water at a ratio of 1:1.5 to make mortar, and inject it into the layer to be plugged. The treatment radius is 3.8m, and after 36 hours of curing, the drilling plug is tested to be 35MPa qualified.

[0024] See Table 1 for the proportions of Embodiment 4 to Embodiment 8 and their performance evaluation indexes.

[0025] The proportioning of table 1 embodiment 4 to embodiment 8 and performance eval...

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Abstract

The invention relates to a chemical plugging agent for oilfield well repair. The chemical plugging agent for oilfield well repair comprises 60-80% of superfine cement, 3-9% of bentonite, 5-8% of calcium oxide, 5-14% of calcium carbonate, 5-7% of asbestos wool, 0.5-0.8% of fluid loss agents, 0.5-0.9% of resistance reducing agents and 0.3-1% of retarders. The plugging agent is good in flowability, safe in construction, large in plugging radius, high in compressive strength after solidification, mainly prepared from inorganic materials, high in aging resistance and long in plugging validity period.

Description

technical field [0001] The invention relates to a chemical plugging agent for oil field workover, which belongs to the technical field of oil field chemistry. Background technique [0002] With the deepening of oilfield development, some blocks have entered the stage of high water cut development, and the comprehensive water cut has reached more than 95%. At the same time, the problem of well conditions has become increasingly prominent, especially in some old wells, due to the long service life of the oil layer casing, the cementing cement has not completely sealed the oil layer casing, coupled with perforation and repeated hole filling, and management measures in the production process. Improper, layered operations, casing deformation, damage, etc. have caused mud and water to flow out of the formation, seriously affecting the normal production of oil and water wells. Therefore, effective plugging of the water-producing layer is an important measure to stabilize productio...

Claims

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Application Information

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Patent Type & AuthorityPatents(China)
IPC IPC(8): C09K8/467
CPCC09K8/426C09K8/467C09K2208/08
Inventor赵泽宗于鑫杨洪源李冰曾令锐宫志勇张友张兵涛
OwnerCHINA PETROLEUM & CHEM CORP