CN104632122A - Block profile control well selection method used in low-permeability fractured reservoir - Google Patents

Abstract

A block profile control well selection method used in a low-permeability fractured reservoir belongs to the technical field of petroleum industry. Introducing original thickness and original permeability, providing an IPI well selection method, performing well selection according to an IPI calculation result, and then performing profile control by adopting a profile control process; the well selection method for block profile control is to select a well meeting the following conditions: testing the wellhead pressure drop curve of each water well in the profile control block; working systems of adjacent wells are not changed in the testing time period, the testing time of the 1 st well of each block is 24 hours, the stage that the pressure drop tends to be gentle is found out, and the testing time of the block is determined; sequentially testing other water injection wells in the block; after the test is finished, drawing a pressure drop curve of the wellhead of the water injection well; the wells below the block average IPI value were selected as profile control wells, and the wells around the block average dimensionless IPI value and above the block average IPI value were not treated.

Description

A kind of low permeability fractured type oil reservoir use for Block Profile Control well choosing method

Technical field

The present invention relates to a kind of low permeability fractured type oil reservoir use for Block Profile Control well choosing method, belong to oil work technical field.

Background technology

Current domestic representative decision-making technic mainly contains: PI decision-making technic, RE decision-making technic, the tracer decision-making technic of China University Of Petroleum Beijing's research, and the RS decision-making technic of Oil Exploration in China developmental research institute development.Wherein PI decision-making technic is that Petroleum Univ. (East China) professor Zhao Fulin equals to propose and utilizes well head falloff curve to select well decision-making technic the nineties.Generally apply at tens, middle and high infiltration oil field blocks such as triumph, grand celebration, Central Plains, effect is better, but for Fracture with low permeability oil reservoir, there is erroneous judgement profile control well, these methods also have certain limitation.

Summary of the invention

In order to overcome the deficiencies in the prior art, the invention provides a kind of low permeability fractured type oil reservoir use for Block Profile Control well choosing method.

Low permeability fractured type oil reservoir use for a Block Profile Control well choosing method, containing following steps;

Introducing original thickness, original permeability proposes IPI well choosing method, carry out selecting well according to IPI result of calculation, carrying out profile control according to then adopting profile control technology;

The well choosing method of Block Profile Control chooses the well met the following conditions:

(1) the well head pressure depression curve of well each in profile control block is tested; In testing time section, the working system of contiguous each well does not change, and the 1st mouthful of 24 hours well testing time of each block, finds out the stage that drop of pressure tends towards stability, determines the testing time of block;

(2) successively other water injection well in block is tested;

(3) after test completes, the falloff curve of wellhead of water injection well is drawn;

(4) calculate the PI value of each well, then calculate the zero dimension IPI value of each well;

$\mathrm{PI}=\frac{{\∫}_0^{t}p\left(t\right)\mathrm{dt}}{t}$

$\mathrm{IPI}=\frac{k_{i}h}{1.842\×{10}^{-3}\mathrm{q\μ}}\·\mathrm{PI}$

(5) select the well lower than the average IPI value of block to be profile control well, the well near block average zero dimension IPI value and higher than the average IPI value of block is disregarded.

Advantage of the present invention is:

(1) zero dimension IPI value considers the original permeability of reservoir, eliminates the pressure relief capability of reservoir own to the impact of falloff curve.And the size of zero dimension PI value and reservoir permeability increase multiple (k/ki) and are inversely proportional to.Namely the predominant pathway growth rank formed in current reservoir is higher, and it is larger that permeability increases multiple, and zero dimension PI value is less;

(2) zero dimension IPI value is tolerance Reservoir Seepage ability being strengthened to degree, working system before its size and water injection well closing well, as irrelevant in injection pressure, injection rate etc., therefore in same block different Injection Well zero dimension PI value between can mutually compare;

(3) IPI value calculates simple, and result is only relevant with choosing of computing time.The principle chosen computing time is: in closed-in time t, and testing well will complete main drop of pressure amplitude, and calibration curve information can reflect pit shaft, the formation information of wellbore region in the certain limit of near wellbore zone.

Detailed description of the invention

Obviously, the many modifications and variations that those skilled in the art do based on aim of the present invention belong to protection scope of the present invention.

Embodiment 1: a kind of low-permeability oilfield Block Profile Control well choosing method

For being that main block profile control well selection accuracy rate is not high with dynamic-analysis method, the problems such as the cycle is long, the invention provides a kind of effective well choosing method adapting to block integral profile control, and then improve measure specific aim and efficient, improve block waterflooding development effect.

Select the region that comprehensive water cut is high, water injection well cementing quality is good, leaks phenomenon without channelling and interlayer string.Test the water injection well falloff curve of region or block in flakes, calculate IPI value and the average IPI value of block of corresponding well, select the well lower than the average IPI value of block to be profile control well, sorted by IPI value is ascending by profile control well, the well that prioritizing selection IPI value is little carries out profile control.

Below in conjunction with detailed description of the invention, the present invention is further illustrated:

(1) the well head pressure depression curve of well each in block is tested.In testing time section, the working system of contiguous each well does not change, and the 1st mouthful of 24 hours well testing time of each block, finds out the stage that drop of pressure tends towards stability, determines the testing time of block.

(2) successively other water injection well of block is tested.

(3) after test completes, the falloff curve of wellhead of water injection well is drawn.

(4) calculate the PI value of each well, then calculate the zero dimension IPI value of each well.

$\mathrm{PI}=\frac{{\∫}_0^{t}p\left(t\right)\mathrm{dt}}{t}$

$\mathrm{IPI}=\frac{k_{i}h}{1.842\×{10}^{-3}\mathrm{q\μ}}\·\mathrm{PI}$

(5) select the well lower than the average IPI value of block to be profile control well, the well near block average zero dimension IPI value and higher than the average IPI value of block is disregarded.

As mentioned above, embodiments of the invention are explained, but as long as do not depart from inventive point of the present invention in fact and effect can have a lot of distortion, this will be readily apparent to persons skilled in the art.Therefore, such variation is also all included within protection scope of the present invention.

Claims (1)

1. low permeability fractured type oil reservoir use for a Block Profile Control well choosing method, it is characterized in that containing following steps;

Introducing original thickness, original permeability proposes IPI well choosing method, carry out selecting well according to IPI result of calculation, carrying out profile control according to then adopting profile control technology;

The well choosing method of Block Profile Control chooses the well met the following conditions:

(1) the well head pressure depression curve of well each in profile control block is tested; In testing time section, the working system of contiguous each well does not change, and the 1st mouthful of 24 hours well testing time of each block, finds out the stage that drop of pressure tends towards stability, determines the testing time of block;

(2) successively other water injection well in block is tested;

(3) after test completes, the falloff curve of wellhead of water injection well is drawn;

(4) calculate the PI value of each well, then calculate the zero dimension IPI value of each well;

$\mathrm{PI}=\frac{{\∫}_0^{t}p\left(t\right)\mathrm{dt}}{t}$

$\mathrm{IPI}=\frac{k_{i}h}{1.842\×{10}^{-3}\mathrm{q\μ}}\·\mathrm{PI}$

(5) select the well lower than the average IPI value of block to be profile control well, the well near block average zero dimension IPI value and higher than the average IPI value of block is disregarded.