A water quality decision-making method for oilfield injection in high water-cut period based on water quality sensitivity

A technology of high water cut, oilfield water injection, applied in earthwork drilling, data processing applications, wellbore/well components, etc., can solve the problems of unclear change laws, no clear decision-making water injection water quality technical policy boundaries, etc.

Active Publication Date: 2021-01-22
CHINA UNIV OF PETROLEUM (EAST CHINA)
View PDF5 Cites 0 Cited by
  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Problems solved by technology

[0003] However, in view of the current horizontal and vertical heterogeneity requirements of oil reservoirs, in the existing oilfield water quality recommendation standards, the change law of the permeability retention rate of different reservoirs with different water quality and dimensionless injection volume is not clear, lacking Based on the current recommended water quality standards, a comprehensive analysis of the law of reservoir permeability decay
At the same time, the injection water quality has not been re-selected to control the reservoir permeability of the entire water injection system under the condition of comprehensive consideration of water injection quality and water injection history. There is no clear technical policy limit for decision-making of water injection quality, and there is a lack of a set that is compatible with reservoir development. A dynamic evaluation and decision-making method that can evaluate, constrain, and determine the feasibility of water quality schemes

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 water quality decision-making method for oilfield injection in high water-cut period based on water quality sensitivity
  • A water quality decision-making method for oilfield injection in high water-cut period based on water quality sensitivity
  • A water quality decision-making method for oilfield injection in high water-cut period based on water quality sensitivity

Examples

Experimental program
Comparison scheme
Effect test

Embodiment 1

[0065] A water quality decision-making method for oilfield water injection in high water-cut periods based on water quality sensitivity. The specific implementation needs to know the geological situation of the block where the water injection system is located, including: well spacing, row spacing, cumulative water injection volume and For injection volume, and control of reservoir thickness, porosity and permeability, the Lai 38 fault block in Guangli Oilfield is selected for analysis, including the following steps:

[0066] (1) Calculate the pore volume V of the controlled reservoir of each well φi ; Suppose the controlled oil supply area of ​​a single well is F=well spacing×row spacing, the unit is m 2 , the total number of wells in the water injection system is N, then:

[0067] V φi =Fhφ(I)

[0068] In the formula (I), h is the effective thickness of the oil layer, m;

[0069] φ is the average effective porosity;

[0070] i is the label of the water injection well, i...

Embodiment 2

[0123] According to the water quality sensitivity decision-making method for oilfield water injection in high water cut period described in Example 1, the difference is:

[0124] Select Xing3-4 area of ​​Xingshugang Oilfield for analysis, the average permeability of formation before water injection development is 900.3×10 -3 μm 2 According to Table 2, it can be seen that the water quality of the injection water is Grade IV. Calculated from steps (1) to (4), the current average permeability of the formation is 300.7×10 -3 μm 2 , the water quality standard number is 7.2, according to Table 3, it can be seen that the optimal water quality for water injection development should be Grade III water quality. The field test of improving the water quality from grade IV to grade III shows that the oil recovery rate of this block is increased by 6.3%, which shows that the water quality determined by this water injection quality decision method is correct.

Embodiment 3

[0126]According to the water quality sensitivity decision-making method for oilfield water injection in high water cut period described in Example 1, the difference is:

[0127] Selecting the South 1 area of ​​Sartu Oilfield for analysis, the average permeability of the formation before water injection development was 1646.1×10 -3 μm 2 , according to Table 2, we can see that the current water quality of injection water is V-level water quality. Calculated from steps (1) to (4), the current average permeability of the formation is 943.6×10 -3 μm 2 , the water quality standard number is 7.1, according to Table 3, it can be seen that the optimal water quality for water injection development should be grade IV water quality. The field test of improving the water quality from grade V to grade IV shows that the oil recovery rate of this block has increased by 8.2%, which shows that the water quality determined by this water injection quality decision method is correct.

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 method for determining the injected water quality of a high water-cut period oilfield based on water quality sensitivity. The method includes the following steps of (1) calculating the pore volume Vphii of a controlled reservoir of each well; (2) calculating the dimensionless injection quantity Qi of each well; (3) calculating the average permeability of the controlled reservoir of each well before water injection development, the permeability water quality sensitivity coefficient thetai of the controlled reservoir of each well under the current injected water quality and the current permeability Ki of the controlled reservoir of each well considering the water injection history; (4) calculating the average permeability of controlled reservoirs of a current waterinjection system; (5) based on water quality recommendation standards, determining which water injection quality should be specifically selected for the current water injection system. The method isbeneficial to solving the contradiction of high water-cut period development and meeting the water injection demand of reservoirs after long-term water injection development, and also has important significance for reducing the energy consumption, saving the cost and adapting to the low-oil-price era.

Description

technical field [0001] The invention belongs to the technical field of water quality selection for sandstone oil reservoir injection in high water cut period, and specifically relates to a water quality decision method in high water cut period based on water quality sensitivity of sandstone permeability. Background technique [0002] As most of my country's major oil fields have been developed by water flooding, they have now entered the stage of high water-cut production. In the process of water flooding development, the quality of injection water will directly affect the development effect of reservoir water flooding and the degree of damage to the reservoir. In high water-cut sandstone reservoirs, long-term water injection, especially substandard water injection, will cause serious clogging of the reservoir, thus causing damage to the permeability of the reservoir. , the impurities in the water fill the pores in the formation; second, the greater the flow rate of the inj...

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): E21B43/20G06Q10/06G06Q50/02
Inventor 王建忠徐进杰孙致学刘均荣宋宪坤付颖超
Owner CHINA UNIV OF PETROLEUM (EAST CHINA)
Who we serve
  • R&D Engineer
  • R&D Manager
  • IP Professional
Why Eureka
  • Industry Leading Data Capabilities
  • Powerful AI technology
  • Patent DNA Extraction
Social media
Try Eureka
PatSnap group products

Browse by: Latest US Patents, China's latest patents, Technical Efficacy Thesaurus, Application Domain, Technology Topic.

© 2024 PatSnap. All rights reserved.Legal|Privacy policy|Modern Slavery Act Transparency Statement|Sitemap