CN103266870A - Method and system for determining damage radius of oil and gas reservoir water blocking - Google Patents

Abstract

The invention provides a method for determining the damage radius of oil and gas reservoir water blocking. The determining method includes the steps that aqueous phase movement speed is determined according to capillary force Pc and a displacement effect on aqueous phase by differential pressure delta P between liquid phase pressure in a shaft and formation pressure; the water amount of the aqueous phase entering a reservoir stratum is determined according to the aqueous phase movement speed and the contact sectional area between the aqueous phase and the reservoir stratum; the radius of the aqueous phase invading into the reservoir stratum is calculated according to the water amount of the aqueous phase entering the reservoir stratum, the pore channel sectional area of the reservoir stratum and porosity. The invention further provides a system for determining the damage radius of the oil and gas reservoir water blocking. The determining method can forecast accurately the invading radius of the gas well water blocking without the need for rock core experiments and well testing, and can calculate dynamic invading radiuses in kinds of operation, so that the system is easy to operate and small in calculation error. The water blocking damage radius of long-period operation measures can be described accurately, and the defect that the water blocking damage radius can not be obtained through a routine experimental method is remedied.

Description

A kind of definite method and system of oil-gas reservoir water blocking damage radius

Technical field

The present invention relates to a kind of assessment technique of oil-gas reservoir water blocking damage, relate in particular to a kind of definite method and system of oil-gas reservoir water blocking damage radius.

Background technology

Water blocking damage is the key factor that influences gas well deliverability, because hypotonic gas reservoir hole duct is little, contacts the back with secondary water and can enter reservoir under the effect of capillary force.When the duct more hour, capillary force is more big, the radius that water enters reservoir is more big.In the self-priming process, it is more many to suck on the one hand the water yield, and its suffered resistance is more big; Owing to the viscous resistance effect, gas can not be discharged fast on the other hand, and the water that sucks is certainly passed gas gradually along the self-priming direction, and the gas pressure increase has limited water self-priming speed like this.

At present, mainly be by the in-house laboratory investigation water blocking damage, by rock core being pumped into the permeability variation of water front and back, draw the extent of injury of rock core.This method adopts the rock core volume little when simulation water blocking damage rate, and water namely can stop to suck after being drawn onto to a certain degree.When adopting conventional core to carry out the water blocking damage experiment, because rock core length little (in the 5cm), initial stage self-priming speed is fast, but along with the increase of water phase saturation, capillary force can be more and more littler, stops substantially sucking in 1h.

But when boring completion or kill job, liquid phase and stratum area time of contact are big, and self-priming time is long, and radius of vulnerability is big, and operation rear section well production declines to a great extent or loses production capacity.If the water blocking damage degree that only adopts normal experiment to calculate then can only be estimated the injury of nearly well area, can't assess the water radius of influence that bores completion or kill-job process.

In order to find out in the various operation process, the water lock then must be analyzed the entire job process dynamically to the influence of gas well deliverability, analyzes the radius of water blocking damage.Long when kill-job or activity duration, when the water invasion radius was big, conventional perforation mode may not test out true production capacity, need take extensive de-plugging and well stimulation.Only be difficult to judge dynamically degree and the radius of water blocking damage according to present experimental technique, lack necessary technology when formulating concrete work measure and support.

Summary of the invention

The application provides a kind of definite method of oil-gas reservoir water blocking damage radius, and this determines that method comprises:

According to capillary force P _cAnd the displacement effect of the water of pressure differential deltap P of the interior liquid phase pressure of pit shaft and strata pressure, determine the water movement velocity;

Contacting section according to described water movement velocity and water and reservoir is long-pending, determines that water enters the water yield of reservoir;

Enter the water yield of reservoir, the duct sectional area of reservoir according to described water, degree of porosity calculates the radius that water is invaded reservoir.

Preferably, according to the capillary force empirical curve of rock core, determine the capillary force P under the reservoir conditions _C1, calculate described capillary force P according to following expression again _c:

P _c＝1/15P _c1，

P _C1Capillary force for the gassiness under the reservoir conditions (moisture) saturation ratio correspondence.

Preferably, determine described pressure differential deltap P according to following expression:

ΔP＝P _wf-P _i，

P _WfBe bottom pressure, P _iBe the stratum static pressure.

Preferably, determine the water movement velocity according to following expression:

$v_w=\frac{k_w}{{\mathrm{\μ}}_w}\·\frac{\mathrm{\Δp}+p_c}{x}$

Wherein, V _wBe the water movement velocity; K _wBe water phase permeability; μ _wBe aqueous viscosity; X is the distance of motion.

Preferably, determine to enter the water yield of reservoir according to following expression:

$N_{\mathrm{wt}}^2=A\·V_w\·t\·A\·x\·\mathrm{\φ}\·(S_{\mathrm{wf}}-S_{\mathrm{wi}})=A^2\frac{K_w\mathrm{\φ}(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w}t$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is core porosity; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; X is the distance of motion; T is the time of contact of liquid phase and reservoir in the operation process.

Preferably, calculate the radius that water is invaded reservoir according to following expression:

$L_c=\frac{N_{\mathrm{wt}}}{\mathrm{A\φ}}=\sqrt{\frac{K_{w}t(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w\mathrm{\φ}}}$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is the core porosity of reservoir; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; T is the time of contact of liquid phase and reservoir in the operation process.

Preferably, determine water saturation S according to following expression _Wf:

Work as S _WiDuring 〉=Sor, S _WfBe P _C2The water saturation that-Δ P is corresponding;

Work as S _WiDuring＜Sor, S _WfBe P _C2-Δ P-P _cCorresponding water saturation;

P _C2For with primitive rock water saturation S in the heart _WiCorresponding capillary force, Sor are irreducible water saturation.

The application also provides a kind of oil-gas reservoir water blocking damage radius fixed system really, and this system comprises:

The first parameter determination module is used for according to capillary force P _cAnd the displacement effect of the water of pressure differential deltap P of the interior liquid phase pressure of pit shaft and strata pressure, determine the water movement velocity;

The second parameter determination module is used for amassing according to the contacting section of described water movement velocity and water and reservoir, determines that water enters the water yield of reservoir;

The water blocking damage radius is the cover half piece really, is used for according to the water yield of determining that water enters reservoir, and the duct sectional area of reservoir, degree of porosity calculate the radius that water is invaded reservoir.

Preferably, the described first parameter determination module is used for the capillary force empirical curve according to rock core, determines the capillary force P under the reservoir conditions _C1, calculate P according to following expression again _c:

P _c＝1/15P _c1，

P _C1Capillary force for the gassiness under the reservoir conditions (moisture) saturation ratio correspondence.

Preferably, the described first parameter determination module is used for determining described pressure differential deltap P according to following expression:

ΔP＝P _wf-P _i，

P _WfBe bottom pressure, P _iBe the stratum static pressure.

Preferably, described first parameter module is used for determining the water movement velocity according to following expression:

$v_w=\frac{k_w}{{\mathrm{\μ}}_w}\·\frac{\mathrm{\Δp}+p_c}{x}$

Wherein, V _wBe the water movement velocity; K _wBe water phase permeability; μ _wBe aqueous viscosity; X is the distance of motion.

Preferably, described second parameter module is used for the water yield of determining to enter reservoir according to following expression:

$N_{\mathrm{wt}}^2=A\·V_w\·t\·A\·x\·\mathrm{\φ}\·(S_{\mathrm{wf}}-S_{\mathrm{wi}})=A^2\frac{K_w\mathrm{\φ}(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w}t$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is core porosity; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; X is the distance of motion; T is the time of contact of liquid phase and reservoir in the operation process.

Preferably, described water blocking damage radius really the cover half piece be used for calculating the radius that water is invaded reservoir according to following expression:

$L_c=\frac{N_{\mathrm{wt}}}{\mathrm{A\φ}}=\sqrt{\frac{K_{w}t(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w\mathrm{\φ}}}$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is the core porosity of reservoir; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; T is the time of contact of liquid phase and reservoir in the operation process.

Preferably, determine the S of water saturation according to following expression _Wf:

When Swi 〉=Sor, S _WfBe P _C2The water saturation that-Δ P is corresponding;

When Swi＜Sor, S _WfBe P _C2-Δ P-P _cCorresponding water saturation

P _C2For with primitive rock water saturation S in the heart _WiCorresponding capillary force, Sor are irreducible water saturation.

The present invention mainly comprises two parts: parameter selected part, radius of vulnerability calculating section.Wherein key parameter obtains part and mainly comprises the pit shaft water saturation variation corresponding with net-head, different pressures between reservoir, reservoir capillary force size, water phase permeability etc.; The radius of vulnerability calculating section calculates the radius of vulnerability of different time correspondence mainly by the various equations of motion in the derivation water blocking damage forming process.

When derivation water blocking damage radius, taken all factors into consideration the pressure reduction of pit shaft and stratum in capillary force and the operation process to the displacement effect of water.Go out the movement velocity of water by input water phase permeability and viscosity calculations; Enter the reservoir amount according to the long-pending water accumulative total that calculates of the contacting section of movement velocity and water and reservoir; Non-homogeneity, duct sectional area, degree of porosity according to reservoir calculates the radius that water is invaded reservoir again.

The embodiment of the invention has following advantage:

1, the embodiment of the invention has been considered net-head between pit shaft and the reservoir to the influence of water blocking damage, and the factor of consideration is many, and result of calculation and on-site actual situations error are little.

2, the water blocking damage radius of the work measure that the embodiment of the invention is can the accurate description cycle long has remedied the defective that the normal experiment method can not draw the water blocking damage radius.

3, the embodiment of the invention method that do not need to carry out core experiment and well testing namely can accurately be predicted the radius that gas well water lock is invaded, and the dynamic invasion radius can also calculate various operation the time, and this system is simple to operate, error of calculation is little.

4, the embodiment of the invention can instruct the water blocking damage gas well to select reasonably test or yield-increasing technique targetedly.

Description of drawings

Fig. 1 is the schematic diagram of the capillary force curve map of the embodiment of the invention;

Fig. 2 is that the water of the embodiment of the invention is invaded the reservoir saturation ratio with the change in radius schematic diagram;

Fig. 3 dynamically invades the schematic diagram of the radius of reservoir for the water of the embodiment of the invention.

The specific embodiment

Hereinafter will be elaborated to embodiments of the invention by reference to the accompanying drawings.Need to prove that under the situation of not conflicting, the embodiment among the application and the feature among the embodiment be any combination mutually.

The present invention comprises that mainly key parameter obtains part, water blocking damage radius calculation part.Be mainly following steps:

Step 1: liquid phase pressure and strata pressure in the pit shaft during according to operation calculate net-head Δ P;

In boring completion or stimulation work process, need to use various well killing fluids, to guarantee that the fluid in the reservoir can blowing.According to well head pressure (P _{Well head}) and pit shaft head of liquid (P _{Fluid column}) convert out bottom pressure P _Wf=P _{Fluid column}+ P _{Well head}Suppose that the stratum static pressure is P _i, Δ P=P then _Wf-P _i

If bore in completion or the test process, the head of liquid in the pit shaft is greater than the stratum reset pressure, and then Δ p＞0 shows that the liquid phase invasion radius is bigger; If head of liquid is less than or equal to the stratum reset pressure, then Δ p≤0 shows that the speed on water intrusion stratum is suppressed.

Step 2: according to the capillary force empirical curve of rock core, find out the capillary force size P under the reservoir conditions _c

According to the basic geology data, find out the capillary force size P of gassiness (moisture) the saturation ratio correspondence under the reservoir conditions _C1, see shown in Figure 1.Again the capillary force of laboratory condition is converted P under the reservoir conditions _c=1/15P _C1

Step 3: take all factors into consideration net-head Δ P and capillary force P in the step 1 _cUnder the effect, the variation S of water saturation _Wf

Enter in the process of reservoir at water, the liquid phase saturation ratio in the hole can constantly change.Water saturation presents the funnel-form distribution in the zone of water blocking damage, sees shown in Figure 2.Along with the increase of water saturation, capillary force can be more and more littler, and then stop self-priming.

Determine S _WfShi Shouxian need judge the initial aqueous S that satisfies _WiAnd and irreducible water saturation Sor between relation:

Work as S _WiDuring 〉=Sor, then the influence of capillary force can be ignored, and the saturation ratio that this moment, water was invaded is only relevant with net-head Δ P.By primitive rock in the heart water saturation and capillary force graph of a relation (owing to only be that water is gentle in the hole of gas reservoir, i.e. Sw=100-S _g, can change mutually gassiness and water saturation) on find out S _WiCorresponding capillary force P _C2, and then find capillary force P _C2With the difference of net-head Δ P (be P _C2-Δ P) corresponding water saturation is S _Wf

Work as S _WiDuring＜Sor, show that then intrusion has the displacement effect to capillary force to water, deducts net-head Δ P and capillary force P this moment on the basis of Pc2 _c, and then to find difference (be P _C2-Δ P-P _c) corresponding water saturation, be S _Wf

Step 4: t time of contact that determines liquid phase and reservoir in the operation process.

Statistics kill-job or well shut-in period, the time t that liquid phase contacts with the stratum in the pit shaft.

Step 5: according to reservoir basic physical properties parameter, find out parameters such as aqueous viscosity, water effective permeability, reservoir porosity.

Step 6: according to the expression formula of the water blocking damage radius of deriving, calculate the water blocking damage radius of different time.

The derivation of the expression formula of water blocking damage radius is as follows:

According to water lock core experiment and CT scan, draw the gas drive water model and meet bundle model, ignore the influence of gas phase gravity simultaneously.Draw according to the darcy flow law:

$v_w=-\frac{k_w}{{\mathrm{\μ}}_w}\·\frac{{\∂p}_w}{\∂x}---\left(1\right)$

In boring completion or operation process, the pressure of fluid column may then can form an extra pressure differential deltap P greater than (or approaching) stratum static pressure in the pit shaft, and water is driven in the stratum.

So (1) in the formula:

p _w＝p _g-(Δp+p _c) (2)

In the experiment of water self-priming, water is to move vertically upward, is approximately the piston type motion.So:

$\frac{{\∂p}_w}{\∂x}=\frac{\∂(p_g-\mathrm{\Δp}-p_c)}{\∂x}=-\frac{\mathrm{\Δp}+p_c}{x}---\left(3\right)$

$v_w=\frac{k_w}{{\mathrm{\μ}}_w}\·\frac{\mathrm{\Δp}+p_c}{x}---\left(4\right)$

Suppose that original rock core water containing saturability is S _Wi, water enters that water saturation is S behind the stratum _Wf, then accumulation enters the water yield N in the reservoir _WtFor

N _wt＝Axφ(S _wf-S _wi) (5)

Absorption speed q _wFor

$q_w=\frac{{\mathrm{dN}}_{\mathrm{wt}}}{\mathrm{dt}}=A\·V_w=\frac{K_{w}A(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_{w}x}---\left(6\right)$

(6) formula is carried out integration,

$N_{\mathrm{wt}}=A\·V_w\·t=A\frac{K_{w}A(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_{w}x}t---\left(7\right)$

Both sides can get with after multiply by (5) formula then

$N_{\mathrm{wt}}^2=A\·V_w\·t\·A\·x\·\mathrm{\φ}\·(S_{\mathrm{wf}}-S_{\mathrm{wi}})=A^2\frac{K_w\mathrm{\φ}(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w}t---\left(8\right)$

Invading the reservoir radius for water is defined as:

$L_c=\sqrt{\frac{V}{\underset{i=1}{\overset{n}{\mathrm{\Σ}}}\frac{A_i}{X_{\mathrm{Ai}}}}}---\left(9\right)$

In (9) formula, owing to need to suppose that the reservoir homogenieity is good, each venturi intrusion is identical, could determine contact area and the corresponding invasion radius of each pore throat, therefore when reservoir is non-homogeneity, can adopt the radius L of following formula calculating water intrusion reservoir _c:

$L_c=\frac{N_{\mathrm{wt}}}{\mathrm{A\φ}}=\sqrt{\frac{K_{w}t(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w\mathrm{\φ}}}---\left(10\right)$

Symbol description in the above formula:

p _c-capillary pressure, MPa;

φ-core porosity, f;

V _w-water movement velocity, m/s;

K _w-water phase permeability, its value is K*K _Rw, mD;

The K-reservoir permeability, mD;

K _Rw-air water oozes water relative permeability in the curve, f mutually;

The distance of x-motion, m;

p _wThe pressure at-water x place in the stratum, MPa;

p _g-gaseous pressure, MPa;

The difference of Δ p-pit shaft and stratum static pressure, MPa.

S _Wi-primitive rock is water saturation in the heart, f;

S _Wf-water enters the water saturation behind the stratum, f;

N _Wt-accumulation enters the water yield in the reservoir, m ³

L _c-liquid phase invasion radius, m;

The V-rock pore volume, m ³

A _iThe contact area an of-Di i duct and water, m ²

X _Ai-water is locked A _iThe radius that individual duct water is invaded, m;

μ _w-aqueous viscosity, mPa.s

The time of contact on water and stratum in the t-pit shaft, h.

Above method synthesis has considered to influence the main drive of water blocking damage, and result of calculation accurately and reliably.Overcome the drawback of the description water blocking damage radius that the conventional core experiment can not be quantitative.

The oil-gas reservoir water blocking damage radius of the embodiment of the invention is fixed system really, mainly comprises the first parameter determination module, and the second parameter determination module and water blocking damage radius be the cover half piece really, wherein,

The first parameter determination module is used for according to capillary force P _cAnd the displacement effect of the water of pressure differential deltap P of the interior liquid phase pressure of pit shaft and strata pressure, determine the water movement velocity;

The second parameter determination module is used for amassing according to the contacting section of water movement velocity and water and reservoir, determines that water enters the water yield of reservoir;

The water blocking damage radius is the cover half piece really, is used for according to the water yield of determining that water enters reservoir, and the duct sectional area of reservoir, degree of porosity calculate the radius that water is invaded reservoir.

The first parameter determination module is used for the capillary force empirical curve according to rock core, determines the capillary force P under the reservoir conditions _C1, again according to above-mentioned expression formula: P _c=1/15P _C1, calculate Pc.

The first parameter determination module is used for according to above-mentioned expression formula: Δ P=P _Wf-P _i, determine pressure differential deltap P.

First parameter module is used for determining the water movement velocity according to above-mentioned expression formula (4);

Second parameter module is for the water yield of determining to enter reservoir according to above-mentioned expression formula (8);

Water blocking damage radius cover half piece really is used for calculating the radius that water is invaded reservoir according to above-mentioned expression formula (10).

Embodiment 1 is that example is calculated the water blocking damage radius with certain gas field 3H well surveying examination situation.This well adopts no solid phase PRD mud drilling, and horizontal section length is 695m; Gas is surveyed obviously unusually in the well logging process, and gas is surveyed full dose about 26～46%, about resistivity 21～29 Ω .m, shows that reservoir gas-bearing property is better.

Adopt the deep penetrating perforating tested productivity, hole depth is 2.5m, and the toe perforating gun has 390m not take out, and remainder is penetrated spud section 100m and barefoot interval 200m, amounts to the 300m horizontal segment; Logging reservoir permeability K is 0.6mD (offset well core permeability 0.42mD), and core porosity φ is 10%, and water saturation is between 53～57%, average out to 54%; Be subjected to natural environment influence during test, soaked 136 hours in the stratum behind the broken glue of perforating fluid, namely liquid phase and stratum time of contact are 136 hours; Reservoir pressure coefficient is 1.16, and test fluid proportion is 1.21; Well opening time is 100 hours during test, and test result is a small amount of gas and 14.5m ³Gas liquid mixture, but with this well shaft bottom be 1371m at a distance of the straight well of 540m at this layer conventionally test aerogenesis ³/ d, and the 3H well location in the structure high-order bit, reservoir properties is better than offset well.Concrete parameter sees Table 1.

Table 1 3H well water phase invasion radius calculating parameter table

Positive differential pressure Δ P by calculating 3H well shaft and reservoir is 2MPa, draws the capillary force p that converts the stratum under original water saturation according to the capillary force empirical curve _cBe 0.3MPa, the pressure that namely acts on the water is 2.3MPa (Δ P+P _c).From the capillary force curve, can draw, at prime stratum water saturation S _Wi=54% o'clock, corresponding capillary force was 1.07MPa, as pressure Δ P+P _cWhen increasing 2.3MPa, corresponding S _WfBe 58%, this moment, saturation ratio changed (S _Wf-S _Wi=58%-54%=4%) be 4%, aqueous viscosity μ _w=1mPa.s.Can draw by the radius of vulnerability that calculates the different time correspondence: the radius that liquid phase enters reservoir is 5m, namely still can not solve the reservoir damage of nearly well area by deep penetrating perforating (hole depth 2.5m), must go out real production capacity level by the fracturing aptitude test, simultaneously as can be seen only under the effect of capillary force water to enter radius be 0.6m, cause water to enter the radius (see figure 3) of reservoir much smaller than the pressure reduction between pit shaft and the stratum.

Though the disclosed embodiment of the present invention as above, the embodiment that described content just adopts for the ease of understanding the present invention is not in order to limit the present invention.Technician in any the technical field of the invention; under the prerequisite that does not break away from the disclosed spirit and scope of the present invention; can do any modification and variation in the details of implementing that reaches in form; but scope of patent protection of the present invention still must be as the criterion with the scope that appending claims was defined.

Claims (14)

1. definite method of an oil-gas reservoir water blocking damage radius is characterized in that, this determines that method comprises:

According to capillary force P _cAnd the displacement effect of the water of pressure differential deltap P of the interior liquid phase pressure of pit shaft and strata pressure, determine the water movement velocity;

Contacting section according to described water movement velocity and water and reservoir is long-pending, determines that water enters the water yield of reservoir;

Enter the water yield of reservoir, the duct sectional area of reservoir according to described water, degree of porosity calculates the radius that water is invaded reservoir.

2. definite method according to claim 1 wherein, according to the capillary force empirical curve of rock core, is determined the capillary force P under the reservoir conditions _C1, calculate described capillary force P according to following expression again _c:

P _c＝1/15P _c1，

P _C1Capillary force for the gassiness under the reservoir conditions (moisture) saturation ratio correspondence.

3. definite method according to claim 1 and 2, wherein, determine described pressure differential deltap P according to following expression:

ΔP＝P _wf-P _i，

P _WfBe bottom pressure, P _iBe the stratum static pressure.

4. definite method according to claim 1 and 2, wherein, determine the water movement velocity according to following expression:

$v_w=\frac{k_w}{{\mathrm{\μ}}_w}\·\frac{\mathrm{\Δp}+p_c}{x}$

Wherein, V _wBe the water movement velocity; K _wBe water phase permeability; μ _wBe aqueous viscosity; X is the distance of motion.

5. definite method according to claim 4, wherein, determine to enter the water yield of reservoir according to following expression:

$N_{\mathrm{wt}}^2=A\·V_w\·t\·A\·x\·\mathrm{\φ}\·(S_{\mathrm{wf}}-S_{\mathrm{wi}})=A^2\frac{K_w\mathrm{\φ}(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w}t$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is core porosity; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; X is the distance of motion; T is the time of contact of liquid phase and reservoir in the operation process.

6. definite method according to claim 5, wherein, calculate the radius that water is invaded reservoir according to following expression:

$L_c=\frac{N_{\mathrm{wt}}}{\mathrm{A\φ}}=\sqrt{\frac{K_{w}t(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w\mathrm{\φ}}}$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is the core porosity of reservoir; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; T is the time of contact of liquid phase and reservoir in the operation process.

7. according to claim 5 or 6 described definite methods, wherein, determine water saturation S according to following expression _Wf:

Work as S _WiDuring 〉=Sor, S _WfBe P _C2The water saturation that-Δ P is corresponding;

Work as S _WiDuring＜Sor, S _WfBe P _C2-Δ P-P _cCorresponding water saturation;

P _C2For with primitive rock water saturation S in the heart _WiCorresponding capillary force, Sor are irreducible water saturation.

8. oil-gas reservoir water blocking damage radius fixed system really is characterized in that this system comprises:

The first parameter determination module is used for according to capillary force P _cAnd the displacement effect of the water of pressure differential deltap P of the interior liquid phase pressure of pit shaft and strata pressure, determine the water movement velocity;

The second parameter determination module is used for amassing according to the contacting section of described water movement velocity and water and reservoir, determines that water enters the water yield of reservoir;

The water blocking damage radius is the cover half piece really, is used for according to the water yield of determining that water enters reservoir, and the duct sectional area of reservoir, degree of porosity calculate the radius that water is invaded reservoir.

9. system according to claim 8, wherein, the described first parameter determination module is used for the capillary force empirical curve according to rock core, determines the capillary force P under the reservoir conditions _C1, calculate P according to following expression again _c:

P _c＝1/15P _c1，

P _C1Capillary force for the gassiness under the reservoir conditions (moisture) saturation ratio correspondence.

10. according to Claim 8 or 9 described systems, wherein, the described first parameter determination module is used for determining described pressure differential deltap P according to following expression:

ΔP＝P _wf-P _i，

P _WfBe bottom pressure, P _iBe the stratum static pressure.

11. according to Claim 8 or 9 described systems, wherein, described first parameter module is used for determining the water movement velocity according to following expression:

$v_w=\frac{k_w}{{\mathrm{\μ}}_w}\·\frac{\mathrm{\Δp}+p_c}{x}$

Wherein, V _wBe the water movement velocity; K _wBe water phase permeability; μ _wBe aqueous viscosity; X is the distance of motion.

12. system according to claim 8, wherein, described second parameter module is used for the water yield of determining to enter reservoir according to following expression:

$N_{\mathrm{wt}}^2=A\·V_w\·t\·A\·x\·\mathrm{\φ}\·(S_{\mathrm{wf}}-S_{\mathrm{wi}})=A^2\frac{K_w\mathrm{\φ}(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w}t$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is core porosity; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; X is the distance of motion; T is the time of contact of liquid phase and reservoir in the operation process.

13. system according to claim 12, wherein, described water blocking damage radius cover half piece really is used for calculating the radius that water is invaded reservoir according to following expression:

$L_c=\frac{N_{\mathrm{wt}}}{\mathrm{A\φ}}=\sqrt{\frac{K_{w}t(S_{\mathrm{wf}}-S_{\mathrm{wi}})\·(\mathrm{\Δp}+p_c)}{{\mathrm{\μ}}_w\mathrm{\φ}}}$

Wherein, N _WtFor accumulation enters the water yield in the reservoir; A is the contact area of duct and water; K _wBe water phase permeability; φ is the core porosity of reservoir; S _WfFor water enters water saturation behind the stratum; S _WiBe primitive rock water saturation in the heart; μ _wBe aqueous viscosity; T is the time of contact of liquid phase and reservoir in the operation process.

14. according to claim 12 or 13 described systems, wherein, determine the S of water saturation according to following expression _Wf:

When Swi 〉=Sor, S _WfBe P _C2The water saturation that-Δ P is corresponding;

When Swi＜Sor, S _WfBe P _C2-Δ P-P _cCorresponding water saturation;

P _C2For with primitive rock water saturation S in the heart _WiCorresponding capillary force, Sor are irreducible water saturation.

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