CN103821485B - Method for predicting water cut increasing rate of water-drive oil field - Google Patents

Abstract

The invention relates to a method for predicting the water cut increasing rate of a water-drive oil field. The method includes the following steps that cylindrical rock samples are taken from a natural rock core of the oil field, a rock core displacement experiment is performed, and a series of parameters such as water saturation Sw, oil phase relative permeability Kro and water phase relative permeability Krw are obtained; irreducible water saturation Swi and residual oil saturation Sor are obtained, and the oil and water viscosity ratio mur is obtained through measurement; the relations between the oil and water relative permeability ratio and the water saturation, the reflected relational expression between the water content and the recovery percentage, and the relational expression between the water cut increasing rate and the recovery percentage are obtained with a power method. According to the method, oil and water relative permeability materials are utilized, a power type mathematical processing method is adopted, the water content and the water cut increasing rate of the oil field are described, the development effect and the development degree of the oil field are analyzed and evaluated, development measures are planned according to the method, the yield of the oil field is reasonably planned and deployed, and more effective guidance can be provided for development of the oil field.

Description

The method of prediction water controlled field water_bearing escalating rate change

Technical field

A kind of the present invention relates to technical field of oil development reservoir engineering, it is more particularly related to prediction water The method of displacing oil-field water_bearing escalating rate change.

Background technology

Oil-water relative permeability is the significant data of reflection underground oil-water two-phase flow characteristic relation, is reservoir engineering research Important foundation data, can be used to oil reservoir prediction moisture content, water-cut variation, water_bearing escalating rate change and recovery ratio etc. and refer to Mark.Deepening continuously with development process, it is (comprehensive that increasing middle and high infiltration sandstone oil reservoir will enter super-high water-cut stage Aqueous it is more than 90%), the exploitation rule of this stage oil reservoir is different from the middle high water-cut development stage.At present, characterize both at home and abroad relatively The method of permeability curve is all based on the conventional treatment of relative permeability experiment, and has no water filling early stage and consider high water filling punching The research of permeability saturation curve form or change sign under brush multiple, carries out long-term injecting water and washes away rear water drive oil theoretical research Seldom.In prior art, on the basis of laboratory obtains water-oil phase permeability and water saturation relation data, calculate biphase Permeability ratio, using exponential processing method, using relational expressionPrediction moisture content and water-cut variation, Carry out lower step analysis work.But its result of calculation is attached in irreducible water saturation and two end points of residual oil saturation with real data Near will produce larger error, in calculating process, this error will be retained, also by the oil pool analysis after being substituted into, right Reservoir performance analysis and programme establishment bring adverse effect.Especially above-mentioned permeability saturation curve characterizing method exist with Lower shortcoming: 1. low water-cut stage oilfield development indexes change, oil-water relative permeability ratio value inconsistent with WATER FLOODING CHARACTERISTIC CURVEWith e^-b·swNot in linear relation, during mining site produces, moisture content rises often more faster；2. the phase under higher amount of water injected There is piecewise nonlinear feature to permeability curve, now the impact to moisture content in actual production for the oil-water relative permeability ratio value Less, then the sign required precision of this stage permeability saturation curve is not high, and it is special that oilfield development indexes change meets WATER DISPLACEMENT CURVES Levy；3. ultra-high water-containing stage flow through oil reservoir feature changes, and phenomenon, oil-water relative permeability occurs upwarping in WATER FLOODING CHARACTERISTIC CURVE RatioWith e^-b·swNo longer as completely in linear relation in routine, line relationship is only suitable for the interlude of permeability saturation curve, And complete permeability saturation curve can not be characterized；4. traditional oil displacement efficiency understanding is contradicted with field pressure coring result: passes System (relative permeability experiment) thinks that oil-water displacement efficiency is generally below 60%, and field pressure coring thinks water drive oil Efficiency can exceed 70%, and conventional permeability saturation curve is unable to the seepage flow characteristics under the high amount of water injected of accurate description.

Content of the invention

In order to solve above-mentioned technical problem of the prior art, it is an object of the invention to provide a kind of prediction water controlled field The method of water_bearing escalating rate change.Method Application of oil-water relative permeability experimental data of the present invention describes Cut of Oilfield And water_bearing escalating rate, come oil reservoir prediction development effectiveness and Exploitation degree, and carry out Planning and Development measure accordingly, deployment of making rational planning for Field output, more can effectively instruct oil field development.

In order to solve to invent described technical problem and realize goal of the invention, present invention employs technical scheme below:

A kind of method of prediction water controlled field water_bearing escalating rate change is it is characterised in that comprise the following steps: to oil field sky So rock core takes cylindric rock sample to carry out rock core displacement test, obtain a series of water saturations sw, oil relative permeability kro, Aqueous phase relative permeability krw data；And obtain irreducible water saturation swi and residual oil saturation sor, measure and obtain profit and glue Degree compares μ_r；Based on power method, try to achieve a, b value according to relational expression (1) application method of least square

$\frac{\mathrm{kro}}{\mathrm{krw}}=a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}---\left(1\right)$

(1) formula is updated to profit flow rate equations and can obtain relational expression (2):

$\mathrm{fw}=\frac{1}{1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}}---\left(2\right)$

Are differentiated to sw in relational expression (2) both sides, obtain relational expression (3):

$\frac{\&partiald;\mathrm{fw}}{\&partiald;\mathrm{sw}}=\frac{(1-\mathrm{sor}-\mathrm{swi})\·\frac{a\·b}{{\mathrm{\μ}}_r}\·\frac{{(\mathrm{sw}-\mathrm{swi})}^{-b-1}}{{(1-\mathrm{sor}-\mathrm{sw})}^{-b+1}}}{{[1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}]}^2}---\left(3\right)$

Water saturation sw is represented with recovery percent of reserves r available relationship formula (4):

Sw=swi+ (1-swi) r (4)

Relational expression (4) is substituted into relational expression (2) formula, obtains the aqueous and recovery percent of reserves of oil-water relative permeability data reflection Relational expression (5):

$\mathrm{fw}=\frac{1}{1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left[\frac{(1-\mathrm{swi})\·r}{1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r}\right]}^{-b}}---\left(5\right)$

Can get water_bearing escalating rate and recovery percent of reserves relation relational expression (6) simultaneously:

$\frac{\&partiald;\mathrm{fw}}{\&partiald;r}=\frac{(1-\mathrm{swi})\·(1-\mathrm{sor}-\mathrm{swi})\·\frac{a\·b}{{\mathrm{\μ}}_r}\·\frac{{[(1-\mathrm{swi})\·r]}^{-b-1}}{{[1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r]}^{-b+1}}}{{[1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left[\frac{(1-\mathrm{swi})\·r}{1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r}\right]}^{-b}]}^2}---\left(6\right).$

Compared with immediate prior art, the method tool of prediction water controlled field water_bearing escalating rate change of the present invention There is a following beneficial effect:

The method of the present invention has higher correlation coefficient using power method form relation formula, describes profit and relatively permeates Rate ratio and the parsing relation of water saturation, can truly reflect underground oil-water displacement relation.The present invention is by oil field sky So rock core takes cylindric rock sample to carry out the data of rock core displacement test, using new effective mathematical processing methods, is moved Aqueous and water_bearing escalating rate change curve in state analysis, intuitively reflects recovery percent of reserves and moisture content and water_bearing escalating rate Relation, analyzes, contrasts the relation of oil reservoir produce reality parameter and theoretical value with this, is that oilfield development program is formulated and lower step is arranged Apply and provide relatively reliable reference frame with Adjusted Option establishment.

Brief description

Fig. 1 is oil-water relative permeability curve datagram described in embodiment 1.

Fig. 2 is the oil-water relative permeability ratio value matched curve figure being obtained using power method and index method described in embodiment 1.

Fig. 3 is moisture content described in embodiment 1 and water_bearing escalating rate change curve.

Specific embodiment

Below with reference to specific embodiment, the method for prediction water controlled field water_bearing escalating rate change of the present invention is done Further elucidated above, with help those skilled in the art the inventive concept of the present invention, technical scheme are had more complete, accurately and Deep understanding；It is to be understood that the description in specific embodiment is all exemplary, and it is not intended to the present invention is protected The restriction of scope, the interest field of the present invention is defined by the claim limiting.

Embodiment 1

Below by way of taking cylindric rock sample to carry out rock core displacement test to certain oil field natural core, to describe of the present invention Prediction water controlled field water_bearing escalating rate change method, described method mainly comprises the steps that

1. carry out rock core displacement test, experimental data is mutually oozed in collection

Certain oil field natural core is taken cylindric rock sample carry out rock core displacement test.In experimentation, the note side of adopting of selection Formula is noted for one end, the other end is adopted, and experiment control condition is to determine liquid injection, level pressure output；Obtain a series of water saturations sw, oil Phase relative permeability kro, aqueous phase relative permeability krw data；And obtain irreducible water saturation swi and residual oil saturation sor, Measure and obtain viscosity ratio of oil and water μ_r；Wherein, the oil-water relative permeability curve data obtaining is as shown in Figure 1.

2. set up method of least square object function

Based on power method and index method, according to Least Square in Processing oil-water relative permeability data as shown in Figure 1, By accompanying drawing 2 it can be seen that using the straightway in the middle of index method only matched curve, there is higher correlation coefficient, for two ends But it is unable to matching, and curve whole process matching then can be realized using the power multiplication of the present invention, correlation coefficient reaches more than 0.99, pole The earth improves fitting precision, reduces analytical error.

3. set up water saturation and recovery percent of reserves, and water_bearing escalating rate and recovery percent of reserves relational expression:

$\mathrm{fw}=\frac{1}{1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}}---\left(2\right)$

To sw, partial derivative is asked to relational expression (2) both sides, obtains relational expression (3):

$\frac{\&partiald;\mathrm{fw}}{\&partiald;\mathrm{sw}}=\frac{(1-\mathrm{sor}-\mathrm{swi})\·\frac{a\·b}{{\mathrm{\μ}}_r}\·\frac{{(\mathrm{sw}-\mathrm{swi})}^{-b-1}}{{(1-\mathrm{sor}-\mathrm{sw})}^{-b+1}}}{{[1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}]}^2}---\left(3\right)$

Water saturation sw is represented with recovery percent of reserves r available relationship formula (4):

Sw=swi+ (1-swi) r (4)

Relational expression (4) is substituted into relational expression (2) formula, obtains the aqueous and recovery percent of reserves of oil-water relative permeability data reflection Relational expression (5):

$\mathrm{fw}=\frac{1}{1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left[\frac{(1-\mathrm{swi})\·r}{1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r}\right]}^{-b}}---\left(5\right)$

Can get water_bearing escalating rate and recovery percent of reserves relation relational expression (6) simultaneously:

$\frac{\&partiald;\mathrm{fw}}{\&partiald;r}=\frac{(1-\mathrm{swi})\·(1-\mathrm{sor}-\mathrm{swi})\·\frac{a\·b}{{\mathrm{\μ}}_r}\·\frac{{[(1-\mathrm{swi})\·r]}^{-b-1}}{{[1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r]}^{-b+1}}}{{[1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left[\frac{(1-\mathrm{swi})\·r}{1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r}\right]}^{-b}]}^2}---\left(6\right).$

Result as shown in Figure 3, using described in the present embodiment method derive produce moisture content and water_bearing escalating rate with Recovery percent of reserves relational expression more can truly reflect the displacement characteristics of underground fluid seepage flow, thus, it is possible to produce for analysis, contrast oil reservoir The relation of actual index parameter and theoretical value, formulates for oilfield development program and lower step measure and Adjusted Option establishment provide more Plus reliable reference guide foundation.

For the ordinary skill in the art, specific embodiment simply combines accompanying drawing and has carried out example to the present invention Property description it is clear that the present invention implements and is not subject to the restrictions described above, as long as employ the method for the present invention design and skill The improvement of the various unsubstantialities that art scheme is carried out, or the not improved design by the present invention and technical scheme directly apply to it Its occasion, all within protection scope of the present invention.

Claims (1)

1. a kind of method of prediction water controlled field water_bearing escalating rate change is it is characterised in that comprise the following steps: natural to oil field Rock core takes cylindric rock sample to carry out rock core displacement test, obtains a series of water saturations sw, oil relative permeability kro, water Phase relative permeability krw data；And obtain irreducible water saturation swi and residual oil saturation sor, measure and obtain profit viscosity Compare μ_r；Based on power method, try to achieve a, b value according to relational expression (1) application method of least square

$\frac{\mathrm{kro}}{\mathrm{krw}}=a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}---\left(1\right)$

(1) formula is updated to profit flow rate equations and can obtain relational expression (2):

$\mathrm{fw}=\frac{1}{1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}}---\left(2\right)$

Are differentiated to sw in relational expression (2) both sides, obtain relational expression (3):

$\frac{\&partiald;\mathrm{fw}}{\&partiald;\mathrm{sw}}=\frac{(1-\mathrm{sor}-\mathrm{swi})\·\frac{a\·b}{{\mathrm{\μ}}_r}\·\frac{{(\mathrm{sw}-\mathrm{swi})}^{-b-1}}{{(1-\mathrm{sor}-\mathrm{sw})}^{-b+1}}}{{[1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left(\frac{\mathrm{sw}-\mathrm{swi}}{1-\mathrm{sor}-\mathrm{sw}}\right)}^{-b}]}^2}---\left(3\right)$

Water saturation sw is represented with recovery percent of reserves r available relationship formula (4):

Sw=swi+ (1-swi) r (4)

Relational expression (4) is substituted into relational expression (2) formula, obtains the aqueous and recovery percent of reserves relation of oil-water relative permeability data reflection Formula (5):

$\mathrm{fw}=\frac{1}{1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left[\frac{(1-\mathrm{swi})\·r}{1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r}\right]}^{-b}}---\left(5\right)$

Can get water_bearing escalating rate and recovery percent of reserves relation relational expression (6) simultaneously:

$\frac{\&partiald;\mathrm{fw}}{\&partiald;r}=\frac{(1-\mathrm{swi})\·(1-\mathrm{sor}-\mathrm{swi})\·\frac{a\·b}{{\mathrm{\μ}}_r}\·\frac{{[(1-\mathrm{swi})\·r]}^{-b-1}}{{[1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r]}^{-b+1}}}{{[1+\frac{1}{{\mathrm{\μ}}_r}\·a\·{\left[\frac{(1-\mathrm{swi})\·r}{1-\mathrm{sor}-\mathrm{swi}-(1-\mathrm{swi})\·r}\right]}^{-b}]}^2}---\left(6\right).$