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

An evaluation method for the influence of chromium ion loss in cracks on the plugging effect of jelly

An evaluation method and chromium ion technology, applied in measuring devices, instruments, scientific instruments, etc., can solve the problems of poor sealing effect of jelly, poor sealing performance of jelly plugging agent, and insufficient measurement of jelly plugging agent.

Active Publication Date: 2017-12-05
PETROCHINA CO LTD
View PDF2 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

In terms of experimental methods, most domestic scholars use the method of physically simulating plugging agent plugging, taking the reverse water flooding pressure gradient as the main reference index, and also attribute the poor performance of gel plugging agent to plugging fractures to gel plugging agent. Insufficient metering of plugging agent does not substantially explain the reason why the jelly is poor in sealing cracks
Some foreign scholars, represented by Seright and Ganguly, have carried out relevant researches. Since the experimental methods used by the two are inconsistent, they have not discussed the influence of crosslinking agent loss in fractures on the plugging effect of jelly plugging agents. come to a unified conclusion

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
  • An evaluation method for the influence of chromium ion loss in cracks on the plugging effect of jelly
  • An evaluation method for the influence of chromium ion loss in cracks on the plugging effect of jelly
  • An evaluation method for the influence of chromium ion loss in cracks on the plugging effect of jelly

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0096] This embodiment provides a method for evaluating the impact of chromium ion loss in cracks on the effect of jelly plugging, comprising the following steps:

[0097] There are four artificially cemented fractured cores. The core size is 4.5cm×4.5cm×40cm. The fracture parameters are all 0.1cm×2.5cm×40cm. The permeability of the core matrix is ​​shown in Table 1.

[0098] Table 1 Core matrix permeability parameters

[0099]

[0100] After the core is saturated with the simulated formation water, the back pressure at the outlet end of the core is adjusted to 50kPa, and the total salinity of the simulated formation water is 7551mg / L; the chromium ion standard jelly plugging agent solution is injected into the core at a constant rate of 0.5mL / min. At the same time, the outflow liquid sample is connected at the outlet end of the rock core, each liquid sample is 5mL, and the injection volume of four rock cores (the multiple of the fracture volume, 1FV=10cm 3 ) are shown in ...

Embodiment 2

[0109] This embodiment provides a method for evaluating the impact of chromium ion loss in cracks on the effect of jelly plugging, comprising the following steps:

[0110] There are four artificially cemented fractured cores. The core size is 4.5cm×4.5cm×40cm. The fracture parameters are all 0.2cm×2.5cm×40cm. The permeability of the core matrix is ​​shown in Table 4.

[0111] Table 4 Permeability parameters of core matrix

[0112]

[0113] After the core is saturated with the simulated formation water, the back pressure at the outlet end of the core is adjusted to 50kPa, and the total salinity of the simulated formation water is 7551mg / L; the chromium ion standard jelly plugging agent solution is injected into the core at a constant rate of 0.5mL / min. At the same time, the outflow liquid sample is connected at the outlet end of the rock core, each liquid sample is 5mL, and the injection volume of four rock cores (the multiple of the fracture volume, 1FV=20cm 3 ) are shown ...

Embodiment 3

[0122] This embodiment provides a method for evaluating the impact of chromium ion loss in cracks on the effect of jelly plugging, comprising the following steps:

[0123] There are four pieces of artificially cemented fractured cores. The core size is 4.5cm×4.5cm×40cm. The fracture parameters are all 0.5cm×2.5cm×40cm. The permeability of the core matrix is ​​shown in Table 7.

[0124] Table 7 Permeability parameters of core matrix

[0125]

[0126]

[0127] After the core is saturated with the simulated formation water, the back pressure at the outlet end of the core is adjusted to 50kPa, and the total salinity of the simulated formation water is 7551mg / L; the chromium ion standard jelly plugging agent solution is injected into the core at a constant rate of 0.5mL / min. At the same time, the outflow liquid samples were taken at the outlet end of the rock cores, each liquid sample was 5mL, and the injection volumes of the four rock cores (multiples of the fracture volume,...

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

PropertyMeasurementUnit
compressive strengthaaaaaaaaaa
Login to View More

Abstract

The invention provides an evaluation method for the influence of chromium ion loss on gel plugging effect in a crack. The evaluation method includes: plugging the crack with a gel plugging agent; evaluating the influence of chromium ion loss on the gel plugging effect as follows specifically: employing a determination method applicable to the concentration of Cr<3+> in the gel plugging agent, determining the concentration of Cr<3+> ejected out of a gel plugging agent liquid sample and the concentration of Cr<3+> in the gel plugging agent after plugging, dividing the concentration of Cr<3+> ejected out of the gel plugging agent liquid sample by the concentration of Cr<3+> in the gel plugging agent to obtain normalized concentration Cnormalization of Cr<3+> ejected out of the liquid sample after plugging, dividing the water-flooding pressure after reverse water flooding under the existence of Cr<3+> loss by the pressure gradient after reverse water flooding under zero Cr<3+> loss to obtain the reverse water flooding normalized pressure gradient dP20 of gel plugging agent plugged crack under the existence of Cr<3+> loss, and evaluating the influence of Cr<3+> loss degree on the gel plugging effect in the crack.

Description

technical field [0001] The invention relates to an evaluation method, in particular to an evaluation method for the influence of chromium ion loss in cracks on the plugging effect of jelly, and belongs to the technical field of petroleum development. Background technique [0002] The fractures in oil reservoirs can be divided into natural fractures and artificial fractures. Natural fractures widely exist in complex reservoirs, especially carbonate reservoirs, while artificial fractures are mainly produced by hydraulic fracturing in low-permeability reservoirs. Under the current widely used water injection development method, these two kinds of fractures have a dual role in improving the development effect of the reservoir: on the one hand, the fractures provide seepage channels for oil and gas, which can improve the seepage capacity of oil and gas from the reservoir to the wellbore, and improve oil and gas production. Efficiency; on the other hand, injected water or formatio...

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): G01N33/00
CPCG01N33/00
Inventor 白英睿熊春明李俊键魏发林江如意黄伟杨立民许寒冰
Owner PETROCHINA CO LTD