Radial well volume fracturing method

Abstract

The invention relates to the technical field of later-stage exploitation of oil and gas fields, and discloses a radial well volume fracturing method. The method comprises the following steps of 100, selecting a target layer of a well to be subjected to radial fracturing, and determining the horizontal maximum principal stress direction and the horizontal minimum principal stress direction of the target layer; 200, determining the fracturing displacement and the fracturing crack length; 300, determining the number of radial water jet holes according to the fracturing displacement and the fracturing crack length in the step 200; 400, performing directional windowing and radial water jet in the direction forming a certain angle with the horizontal minimum principal stress direction, and executing the jet process till all the radial water jet holes are completed; and 500, after the jet process is completed, executing the fracturing process until all fracturing strips are completed. By means of radial water jet in the vertical well, volume fracturing is achieved in the reservoir section, the purpose of similar horizontal well fracturing is achieved, the fracture swept area is enlarged, oil and gas reserves are effectively used, and compared with conventional one-time fracturing, the single-well yield of a low-permeability oil and gas well can be greatly increased.

Description

technical field

[0001] The invention relates to the technical field of post-exploitation of oil and gas fields, in particular to a radial well volume fracturing method. Background technique

[0002] At present, most oil and gas fields in China have entered the late stage of exploitation, and it is necessary to tap the potential of old wells to find remaining oil and repeat fracturing and acidification of old wells to increase production to achieve the purpose of effective production. Radial well technology is one of the most effective ways to find remaining reserves in old wells. But for low-permeability oilfields, fracturing is still needed to obtain better development results. At present, the fracturing of radial wells is basically a simple one-time fracturing, the stimulation scale is small, multi-fracture fracturing has not been realized, and the production capacity cannot be effectively released. Contents of the invention

[0003] The purpose of the present inventio...

Examples

Embodiment 1

[0053] In this example, there are many remaining reserves among wells in the Shahe Formation reservoir in a certain block, and Well A is selected as the experimental well for the radial well volume fracturing experiment. The target layer of Well A is Shahezi Formation, the depth of the oil layer is 2000-2026m, and the thickness of the oil layer is 26m. The specific process includes the following:

[0054] First, for the Shahezi Formation core in Well A, stress testing methods such as core differential strain method and wave velocity anisotropy method were used in the experiment to obtain the horizontal maximum principal stress direction and horizontal minimum principal stress direction of the target layer. The stress test method is not the focus of the present invention, so it will not be repeated here. The directions of the horizontal maximum principal stress are 90° and 270°. Since the direction of the horizontal maximum principal stress is perpendicular to the direction of...

Embodiment 2

[0064] In this embodiment, there are many remaining reserves in the direction of 20° and 170° in the B well of Yingcheng group reservoir in a certain oil field block, and radial well volume fracturing is carried out in order to fully develop these reserves. The depth of the oil layer is 2610-2619m, and the thickness of the oil layer is 9m. The results of previous in-situ stress studies show that the directions of the horizontal maximum principal stress are 95° and 275°. Since the direction of the horizontal maximum principal stress is perpendicular to the direction of the horizontal minimum principal stress, the directions of the horizontal minimum principal stress are 5° and 185°.

[0065] The specific process includes the following:

[0066] Considering that the thickness of the target layer is 2610-2619m, the porosity of the reservoir is 14%, the permeability is 8md, the fracture pressure is 45MPa, and the fracture height is 15m. The crack is 90m long.

[0067] Secondly, ...

Embodiment 3

[0075] In this example, the conventional fracturing of new wells in Yingcheng group in an oilfield block has low production capacity after conventional fracturing, which cannot meet the requirements of economical and effective development. Therefore, the volume fracturing experiment of radial wells is carried out on the new well C. The depth of the oil layer is 2500-2518m, and the thickness of the oil layer is 18m. The results of previous in-situ stress studies show that the directions of the horizontal maximum principal stress are 80° and 260° on average. Since the direction of the maximum horizontal principal stress is perpendicular to the direction of the minimum horizontal principal stress, the directions of the minimum horizontal principal stress are 350° and 170°.

[0076] The specific process includes the following:

[0077] Considering that the thickness of the target layer is 2500-2518m, the porosity of the reservoir is 8%, the permeability is 1md, the fracture pressu...

technical field

[0001] The invention relates to the technical field of post-exploitation of oil and gas fields, in particular to a radial well volume fracturing method. Background technique

[0002] At present, most oil and gas fields in China have entered the late stage of exploitation, and it is necessary to tap the potential of old wells to find remaining oil and repeat fracturing and acidification of old wells to increase production to achieve the purpose of effective production. Radial well technology is one of the most effective ways to find remaining reserves in old wells. But for low-permeability oilfields, fracturing is still needed to obtain better development results. At present, the fracturing of radial wells is basically a simple one-time fracturing, the stimulation scale is small, multi-fracture fracturing has not been realized, and the production capacity cannot be effectively released. Contents of the invention

[0003] The purpose of the present inventio...

Examples

Embodiment 1

[0053] In this example, there are many remaining reserves among wells in the Shahe Formation reservoir in a certain block, and Well A is selected as the experimental well for the radial well volume fracturing experiment. The target layer of Well A is Shahezi Formation, the depth of the oil layer is 2000-2026m, and the thickness of the oil layer is 26m. The specific process includes the following:

[0054] First, for the Shahezi Formation core in Well A, stress testing methods such as core differential strain method and wave velocity anisotropy method were used in the experiment to obtain the horizontal maximum principal stress direction and horizontal minimum principal stress direction of the target layer. The stress test method is not the focus of the present invention, so it will not be repeated here. The directions of the horizontal maximum principal stress are 90° and 270°. Since the direction of the horizontal maximum principal stress is perpendicular to the direction of...

Embodiment 2

[0064] In this embodiment, there are many remaining reserves in the direction of 20° and 170° in the B well of Yingcheng group reservoir in a certain oil field block, and radial well volume fracturing is carried out in order to fully develop these reserves. The depth of the oil layer is 2610-2619m, and the thickness of the oil layer is 9m. The results of previous in-situ stress studies show that the directions of the horizontal maximum principal stress are 95° and 275°. Since the direction of the horizontal maximum principal stress is perpendicular to the direction of the horizontal minimum principal stress, the directions of the horizontal minimum principal stress are 5° and 185°.

[0065] The specific process includes the following:

[0066] Considering that the thickness of the target layer is 2610-2619m, the porosity of the reservoir is 14%, the permeability is 8md, the fracture pressure is 45MPa, and the fracture height is 15m. The crack is 90m long.

[0067] Secondly, ...

Embodiment 3

[0075] In this example, the conventional fracturing of new wells in Yingcheng group in an oilfield block has low production capacity after conventional fracturing, which cannot meet the requirements of economical and effective development. Therefore, the volume fracturing experiment of radial wells is carried out on the new well C. The depth of the oil layer is 2500-2518m, and the thickness of the oil layer is 18m. The results of previous in-situ stress studies show that the directions of the horizontal maximum principal stress are 80° and 260° on average. Since the direction of the maximum horizontal principal stress is perpendicular to the direction of the minimum horizontal principal stress, the directions of the minimum horizontal principal stress are 350° and 170°.

[0076] The specific process includes the following:

[0077] Considering that the thickness of the target layer is 2500-2518m, the porosity of the reservoir is 8%, the permeability is 1md, the fracture pressu...

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