A kind of selective plugging agent and its application

Abstract

The invention relates to a selective blocking agent. It is characterized in that its components and proportions are as follows according to the mass concentration percentage: polyacrylamide 0.3-2%, cross-linking agent 0.4-1.5%, resorcinol 0.5-1.0%, calcium lignosulfonate 0.5-1.5% , polyvinyl alcohol 0.2-0.5%, acid-base agent 0.2-0.5%, stabilizer 0.8-1.8%, sodium chloride 0.2-0.5%, ammonium chloride 0.8-1.5%, and the balance is water. The selective plugging agent is suitable for selective water plugging of casing damaged wells in low-permeability oilfields without moving strings. The selective plugging agent has the characteristics of good pumpability, strong oil-water selectivity, high plugging rate and erosion resistance, and is suitable for chemical water plugging requirements in low-permeability oilfields.

Description

technical field

[0001] The invention relates to a chemical agent in the technical field of petroleum production engineering, in particular to a selective plugging agent and its application in selective water plugging of non-moving pipe strings in casing damaged wells in low-permeability oilfields. Background technique

[0002] Oil well water plugging is an important technical measure of "controlling water and stabilizing oil" implemented from production wells. In this process technology, the selectivity of water shutoff agent is the key, especially for low permeability oil fields, the plugging effect of selective water shutoff is the best. At present, although the selective water shutoff technology has been widely used in domestic oilfields and is becoming more and more mature, the mainstream chemical water shutoff system is mainly used in the test of chemical water shutoff technology, and its effective rate is only 50%. The daily oil increase is 0.1t, the average single we...

Examples

Embodiment 1

[0013] Weigh polyacrylamide, sodium dichromate, organic chromium and the remaining water according to the mass concentration percentages described in Table 1 below, and mix the above-mentioned components to obtain a selective blocking agent. The amide is anionic polyacrylamide with a molecular weight of 12 million. Through indoor experiments, the results of testing the gelling effect of 12 million anionic polyacrylamides are shown in Table 1.

[0014] Table 1

[0015]

Embodiment 2

[0017] Weigh polyacrylamide, sodium dichromate, organic chromium and the remaining water according to the mass concentration percentages described in Table 2 below, and mix the above-mentioned components to obtain a selective blocking agent. The amide is an anionic polyacrylamide with a molecular weight of 17 million. Through indoor experiments, the results of testing the gelling effect of 17 million anionic polyacrylamides are shown in Table 2.

[0018] Table 2

[0019]

Embodiment 3

[0021] Weigh polyacrylamide, sodium dichromate, organic chromium and the remaining water according to the mass concentration percentages described in Table 3 below, and mix the above-mentioned components to obtain a selective blocking agent. The amide is an anionic polyacrylamide with a molecular weight of 19 million. Through indoor experiments, the results of testing the gelling effect of 19 million anionic polyacrylamides are shown in Table 3.

[0022] table 3

[0023]

technical field

[0001] The invention relates to a chemical agent in the technical field of petroleum production engineering, in particular to a selective plugging agent and its application in selective water plugging of non-moving pipe strings in casing damaged wells in low-permeability oilfields. Background technique

[0002] Oil well water plugging is an important technical measure of "controlling water and stabilizing oil" implemented from production wells. In this process technology, the selectivity of water shutoff agent is the key, especially for low permeability oil fields, the plugging effect of selective water shutoff is the best. At present, although the selective water shutoff technology has been widely used in domestic oilfields and is becoming more and more mature, the mainstream chemical water shutoff system is mainly used in the test of chemical water shutoff technology, and its effective rate is only 50%. The daily oil increase is 0.1t, the average single we...

Examples

Embodiment 1

[0013] Weigh polyacrylamide, sodium dichromate, organic chromium and the remaining water according to the mass concentration percentages described in Table 1 below, and mix the above-mentioned components to obtain a selective blocking agent. The amide is anionic polyacrylamide with a molecular weight of 12 million. Through indoor experiments, the results of testing the gelling effect of 12 million anionic polyacrylamides are shown in Table 1.

[0014] Table 1

[0015]

Embodiment 2

[0017] Weigh polyacrylamide, sodium dichromate, organic chromium and the remaining water according to the mass concentration percentages described in Table 2 below, and mix the above-mentioned components to obtain a selective blocking agent. The amide is an anionic polyacrylamide with a molecular weight of 17 million. Through indoor experiments, the results of testing the gelling effect of 17 million anionic polyacrylamides are shown in Table 2.

[0018] Table 2

[0019]

Embodiment 3

[0021] Weigh polyacrylamide, sodium dichromate, organic chromium and the remaining water according to the mass concentration percentages described in Table 3 below, and mix the above-mentioned components to obtain a selective blocking agent. The amide is an anionic polyacrylamide with a molecular weight of 19 million. Through indoor experiments, the results of testing the gelling effect of 19 million anionic polyacrylamides are shown in Table 3.

[0022] table 3

[0023]

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