Unlock instant, AI-driven research and patent intelligence for your innovation.

Radial hole drilling volume fracturing method

A technology of radial drilling and volume fracturing, which is used in the production of fluids, earthwork drilling, wellbore/well components, etc., can solve the problem of increasing the length of cracks in weak sections of the stratum, and it is difficult to achieve the effect of large-area reservoir stimulation , increase the drainage area, etc.

Active Publication Date: 2019-01-18
青岛大地新能源科技研发有限公司
View PDF7 Cites 7 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

For this reason, scholars have proposed radial drilling technology. Radial drilling technology uses high-pressure water jets to break rocks, and hydraulically injects multiple radial wells in different layers and directions of vertical wellbore. The diameter of radial wells is between 35-100mm, and the length The longest can reach 100m, thereby further increasing the oil drainage area, but it is accidental and opportunistic to communicate reservoir fractures only by radial holes drilled. For low-permeability and tight reservoirs, it is difficult to achieve large The effect of area reservoir transformation is not satisfactory after the production is put into operation
[0004] In view of the deficiencies of radial drilling technology and conventional hydraulic fracturing technology, some scholars also use the two technologies in combination, but the design of the two technologies is blind, and most of them still drill in the direction of the maximum principal stress. Only increasing the extension length of the fractures in the weak strata will result in most areas of the reservoir not being stimulated, resulting in unsatisfactory stimulation effects. To solve the existing problems, it is necessary to establish a set of radial drilling design combined with hydraulic fracturing. The reservoir stimulation method forms a spatially complex fracture network after the transformation, and has the effect of volume fracturing. Therefore, the present invention establishes a set of radial drilling volume fracturing design methods for vertical well reservoir stimulation of low permeability and tight oil and gas reservoirs.

Method used

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
View more

Image

Smart Image Click on the blue labels to locate them in the text.
Viewing Examples
Smart Image
  • Radial hole drilling volume fracturing method
  • Radial hole drilling volume fracturing method
  • Radial hole drilling volume fracturing method

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0074] A radial borehole volumetric fracturing method comprising:

[0075] 1) Determining the characteristics and mechanical properties of the reservoir, and determining the expansion law of the fracture network by the characteristics and mechanical properties of the reservoir; step 1) described in the present invention is based on the existing literature (Zhou Liping. Research on the mechanism of directional fracture initiation by radial wells [ D]. China University of Petroleum (East China), 2016.) and in-situ stress field coupling analysis method, to determine the expansion law of radial drilling volume fracturing complex fracture network, this technical feature is clear to those skilled in the art, and can the technical characteristics of the implementation;

[0076] The expansion law of the fracture network is as follows. Among them, the related literature includes, literature [1] Zhou Liping. Research on the directional fracture initiation mechanism of radial well guided...

Embodiment 2

[0087] The radial drilling volume fracturing method as described in embodiment 1, further comprising:

[0088] 4) Combining with different formation types, carry out the design of radial drilling layer and orientation for thick oil layers:

[0089] 4-1) Principles of hole layout for drilling in thick oil layers

[0090] Considering the formation thickness and casing strength, radial drilling in the same layer cannot meet the requirements of longitudinal fracture propagation. In order to ensure the vertical fracture propagation and the formation of complex fracture networks in thick oil layers, the vertical conditions, the following design principles for radial drilling parameters are determined:

[0091] 4-1-1) The drilling orientation is symmetrically arranged longitudinally with the maximum principal stress direction as the symmetry. This scheme is to ensure that the fractures guided by radial wells initiate simultaneously;

[0092] 4-1-2) The distance between the borehole...

Embodiment 3

[0103] The radial drilling volume fracturing method as described in Embodiment 2 further includes: drilling the oil layers according to the types of faults:

[0104] For the method of drilling near short-distance faults, no holes are drilled near short-distance faults, and the azimuths of the drilling are respectively 0 degrees, 30 degrees and 90 degrees from the maximum horizontal principal stress.

[0105] For the method of drilling near long-distance faults, the angle between the drilling direction and the maximum horizontal principal stress is 30 degrees, and the holes are arranged in the opposite direction of the fault according to the method of drilling near the short-distance faults. Such as Figure 10 shown. The drilling length should not be too long.

[0106] In the method for drilling holes near short-distance faults, the length of the hole drilled in the direction of the minimum horizontal principal stress is greater than the length of the hole drilled in other di...

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

PUM

No PUM Login to View More

Abstract

The invention relates to a radial hole drilling volume fracturing method. Based on an interferential stress field formed by a radial wellbore, the radial hole drilling volume fracturing complex seam network expanding law is determined, then based on the seam network expanding conditions, different stratum types are combined, the design of length and direction of drilling holes of a radial well isconducted on thin and thick oil layers, the direction and length of the radial well in the process of implementing the radial hole drilling volume fracturing technology are determined, and finally thedesign range of rushing technology parameters is obtained. By means of the method, the problems existing in the conventional fracturing and radial hole drilling technology are solved, a stratum transforming method combining hole drilling design and hydrofracture is constructed, after transforming, a fracture network with complex space is formed, the volume fracturing effect is achieved, thereforethe working degree of a compact oil and gas reservoir with low-permeability or extra-low permeability is improved, and the development of the low-permeability oil reservoir is better guided.

Description

technical field [0001] The invention discloses a radial drilling volume fracturing method, which belongs to the technical field of transforming low-permeability, ultra-low-permeability and tight oil and gas reservoirs. Background technique [0002] Low-permeability, ultra-low-permeability, and tight oil and gas reservoirs have the characteristics of low porosity, low permeability, and low productivity. It is difficult to obtain industrial oil and gas flow only by conventional development methods. In view of the characteristics of low-permeability and tight reservoirs, the commonly used development methods are mainly The hydraulic fracturing development method forms fractures with high conductivity through hydraulic fracturing, thereby changing the seepage capacity of the reservoir, increasing the oil drainage area, and achieving the effect of increasing production. [0003] In the traditional vertical well hydraulic fracturing technology, fractures usually start near the ver...

Claims

the structure of the environmentally friendly knitted fabric provided by the present invention; figure 2 Flow chart of the yarn wrapping machine for environmentally friendly knitted fabrics and storage devices; image 3 Is the parameter map of the yarn covering machine
Login to View More

Application Information

Patent Timeline
no application Login to View More
Patent Type & Authority Applications(China)
IPC IPC(8): E21B43/26
CPCE21B43/26
Inventor 刘化普张东晓温庆志
Owner 青岛大地新能源科技研发有限公司