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An electrochemical method to accelerate the dissolution of soluble bridge plugs

An electrochemical and bridge plug technology, which is applied in earthwork drilling, wellbore/well components, sealing/isolation, etc., can solve problems affecting construction progress and oil extraction time, and achieve the purpose of inhibiting shale expansion and accelerating The effect of dissolution speed and simple construction process

Active Publication Date: 2022-03-01
PETROCHINA CO LTD
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In the actual construction process of the oil field, it was found that after the fracturing was completed, when it was necessary to put into production quickly, it was found that some bridge plugs were still undissolved and still needed drilling and grinding, which affected the time to get oil on site
In special circumstances such as sand blockage, when it is necessary to speed up the dissolution of the bridge plug, there is often no way to do anything but wait for the bridge plug to dissolve itself, usually 2-3 days, which affects the construction progress
[0003] In order to overcome the existing problem of not being able to quickly dissolve bridge plugs and waiting too long for bridge plugs to dissolve and affecting construction progress, the present invention provides an electrochemical method for accelerating the dissolution of soluble bridge plugs. The present invention uses electrochemical (primary battery and electrolytic Pool) method, using the potential difference of various metals, by giving a certain current on the casing, quickly dissolving soluble balls and soluble bridge plugs, and restoring the wellbore diameter in time, no matter for rapid production or rapid fracturing Construction has very important practical significance

Method used

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  • An electrochemical method to accelerate the dissolution of soluble bridge plugs
  • An electrochemical method to accelerate the dissolution of soluble bridge plugs

Examples

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Embodiment 1

[0027] In order to overcome the existing problem that the bridge plug cannot be quickly dissolved, and the waiting time for the bridge plug to dissolve is too long, which affects the construction progress, the present invention provides such figure 1 and 2 An electrochemical method for accelerating the dissolution of soluble bridge plugs is shown. The present invention uses the electrochemical (primary battery and electrolytic cell) method to use the potential difference of various metals to quickly dissolve by giving a certain current on the casing. Soluble balls and soluble bridge plugs can restore wellbore diameter in time, which is of great practical significance for rapid production or rapid fracturing construction of the next stage.

[0028] An electrochemical method for accelerating the dissolution of soluble bridge plugs, the specific steps are: step 1, for the case where the inner wall of the casing has been internally protected against corrosion,

[0029] First with...

Embodiment 2

[0041] Based on Example 1, in this example, in Step 1, the gas-generating and heat-generating agent A is composed of ammonium chloride and citric acid with a mass ratio of 15: (1-5), which produces gas and heat. The mass concentration of thermal agent A is 25-35%, and the injection volume of gas-generating and heat-generating agent A is 3-5m 3 .

[0042] In the described step one, the guar gum base liquid injection volume is 2-4m 3 .

[0043] In the described step 1, the gas-generating and heat-generating agent B is sodium nitrite, and its mass concentration is 45%-55%; the injection volume of the gas-generating and heat-generating agent B is 3-5m 3 .

[0044] The saturated strong electrolyte in described step 1 and step 2 is potassium chloride, sodium chloride or calcium chloride, and saturated potassium chloride mass concentration is 34.2% at room temperature, and saturated sodium chloride mass concentration is 36.0%, saturated chlorine The concentration of calcium chlor...

Embodiment 3

[0065] Based on Examples 1 and 2, in this example, after staged multi-cluster volumetric fracturing with soluble bridge plugs in Well Hua H-X, it needs to be put into production quickly. After 3 days of shutting down, the bridge plugs are still not dissolved.

[0066] at 2m 3 / min displacement injection 5m 3 15% sulfuric acid, then connect 5m 3 Guar gum base fluid is used for isolation, and water is used to replace it to the position of the bridge plug. After about 1.5 hours, the bridge plug dissolves, and fluid comes out from the wellhead, leading to normal drainage and production.

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Abstract

The invention provides an electrochemical method for accelerating the dissolution of soluble bridge plugs. The specific steps are as follows: Step 1. For the case where the inner wall of the casing has been subjected to internal anti-corrosion, first use a 1-2m 3 / min displacement injection 5‑8m 3 And the mass percentage is 10‑15% hydrochloric acid or sulfuric acid, and then connected to 5‑8m 3 Guar gum base liquid is used for isolation, and replaced with clean water to the bridge plug position; for the case where the inner wall of the casing has not been internally anti-corrosion, firstly use 1-2m 3 / min displacement into saturated strong electrolyte solution, followed by pumping gas-generating heat-generating agent A, guar gum base liquid, gas-generating heat-generating agent B, and replacing it with clean water to the bridge plug position. The present invention utilizes the potential difference of various metals through the electrochemical method (primary battery and electrolytic cell), and by giving a certain current on the casing, the soluble ball and the soluble bridge plug are quickly dissolved, and the borehole diameter is restored in time. It has very important practical significance for quick production or quick implementation of the next stage of fracturing construction.

Description

technical field [0001] The invention relates to the field of petroleum exploitation, in particular to an electrochemical method for accelerating the dissolution of a soluble bridge plug. Background technique [0002] In recent years, hydraulic pumping rapid drilling bridge plug volume fracturing technology has been widely used in the development of shale gas and tight oil in North America, and it is the main stimulation technology for horizontal wells in tight reservoirs abroad. This process has the characteristics of high operating efficiency, large displacement injection for volume fracturing, and multi-cluster perforation. As an emerging horizontal well stimulation technology, it has been widely used in the development of foreign shale gas reservoirs and tight gas reservoirs in recent years. . In order to reduce the drilling and grinding time of bridge plugs and save the cost of grinding and milling, some companies have developed fracturing bridge plugs made of soluble m...

Claims

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Application Information

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Patent Type & Authority Patents(China)
IPC IPC(8): E21B33/134C25F1/04
CPCE21B33/134C25F1/04
Inventor 郭钢慕立俊李楷吴江刘锦周晓群范华波杜现飞鲜晟
Owner PETROCHINA CO LTD