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

A method for enhancing recovery of fractured oil reservoirs

A technology of oil recovery and oil reservoir, which is applied in the field of improving the recovery of fractured oil reservoirs by using osmotic pressure enhancement, and improving the oil recovery of fractured oil reservoirs, and can solve the problem that water flooding cannot improve the oil recovery of reservoir matrix and other issues to achieve the effect of enhancing recovery

Inactive Publication Date: 2017-02-01
CHINA UNIV OF PETROLEUM (EAST CHINA)
View PDF6 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

Since many fractured carbonate reservoirs are mixed-wet or oil-wet, water flooding cannot enhance oil recovery in the reservoir matrix and fractures, and one of the basic issues is how to improve the water flooding sweep coefficient
There is no report on the use of semi-permeable membrane technology for enhanced oil recovery

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
  • A method for enhancing recovery of fractured oil reservoirs
  • A method for enhancing recovery of fractured oil reservoirs

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0014] Make Penetration 32×10 -3 μm 2 The fractured core is first saturated with water with a salinity of 80,000mg / L, and then the simulated crude oil saturated core with 2.0mPa.s is used to establish high-salinity bound water (salinity is 80,000mg / L); take out Put the core in a water absorption and oil discharge instrument filled with 5000mg / L low-salinity water. At this time, the difference between the salinity of the injected water and the salinity of the irreducible water in the fractured core is 16, and record the volume of the discharged crude oil. , the calculated oil recovery rate is 0.2%.

Embodiment 2

[0016] Make Penetration 28×10 -3 μm 2 The fractured core is first saturated with water with a salinity of 80,000mg / L, and then the simulated crude oil saturated core with 2.0mPa.s is used to establish high-salinity irreducible water (salinity is 80,000mg / L); then Inject 0.60mol / L copper ferrocyanide semi-permeable film-forming material into the fractured rock core, close for 12 hours to make the film-forming material form a semi-permeable film on the fracture wall; take out the core, put it in a container containing 5000 mg / L In the water absorption and oil discharge instrument for low-salinity water, the extreme difference between the salinity of the injected water and the salinity of the irreducible water in the fractured core is 16, and the crude oil output volume is recorded, and the calculated oil recovery rate is 12.6 %.

Embodiment 3

[0018] Make Penetration 30×10 -3 μm 2 The fractured core is first saturated with water with a salinity of 40000mg / L, and then the simulated crude oil saturated core with 2.0mPa.s is used to establish high salinity irreducible water (salinity is 40000mg / L); then Inject 0.60mol / L copper ferrocyanide semi-permeable film-forming material into the fractured rock core, close for 12 hours to make the film-forming material form a semi-permeable film on the fracture wall; take out the core, put it in a container containing 5000 mg / L In the water absorption and oil discharge instrument for low-salinity water, the extreme difference between the salinity of the injected water and the salinity of the irreducible water in the fractured core is 8, and the output volume of crude oil is recorded, and the calculated oil recovery rate is 7.8 %.

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 provides a method for increasing the recovery rate of fractured oil reservoirs, in particular a method for increasing the oil recovery rate of low-pressure and low-permeability fractured oil reservoirs by using osmotic pressure enhancement. By injecting a film-forming material into the fractured reservoir, the film-forming material is any one of polyethylene glycol, boric acid cross-linked guar gum, cellulose acetate, silicate and copper ferrocyanide, on the fracture wall Form a semi-permeable membrane, and then inject a kind of water whose salinity is lower than the salinity of the irreducible water of the reservoir into the reservoir, and the salinity difference between the two is more than 2 times. A chemical potential gradient is formed on both sides. Under the action of the chemical potential gradient, the water in the low-salinity water in the fracture passes through the semi-permeable membrane and enters the reservoir matrix, increasing the reservoir pressure or energy to realize self-pumping and oil drainage. The production of crude oil in fractured oil reservoirs with low pressure and low permeability can be greatly increased.

Description

technical field [0001] The invention relates to a method for increasing the recovery rate of a fractured oil reservoir, in particular to a method for increasing the recovery rate of a fractured oil reservoir by using osmotic pressure to increase energy, and belongs to the technical field of petroleum exploitation. Background technique [0002] The oil recovery rate of natural fractured reservoirs is usually very low, especially in medium and high permeability fractured carbonate reservoirs, the oil recovery rate is usually less than 15% of the geological reserves of the reservoir. Generally, it is difficult to provide an oil flow path from matrix to natural fractures in fractured low-permeability reservoirs. Typically, fractured reservoirs are produced using water flooding, but water flooding is only effective for highly permeable naturally fractured reservoirs. Since many fractured carbonate reservoirs are mixed-wet or oil-wet, water flooding cannot enhance the oil recover...

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 Patents(China)
IPC IPC(8): E21B43/22
Inventor 刘德新钟珣郭剑飞肖桂龙史晓斐
Owner CHINA UNIV OF PETROLEUM (EAST CHINA)