CN104675372A - Method for distributing polymer flooding injection rate and polymer flooding produced rate - Google Patents

Abstract

The invention provides a method for distributing polymer flooding injection rate and polymer flooding produced rate. According to the method for distributing the polymer flooding injection rate and the polymer flooding produced rate, remaining geologic reserves of a well group and the average moisture content of the well group are considered comprehensively, the injection rate of various polymer injection wells is distributed, dynamic correlation coefficients of injection and production wells and the water content of single production wells are considered comprehensively, and the produced rate of the various production wells is distributed. By the method, the injection rate and the produced rate of single wheels of a polymer flooding oilfield which is high in heterogeneity and uneven in mining are distributed, and a good technical support is provided for reasonable development of the polymer flooding oil field. By the method, the problem that polymer solution is pushed unevenly in a polymer flooding process is solved, the effective availability of the polymer solution is improved, and the development effect is improved.

Description

A kind of method injecting produced quantity distribution for polymer flooding

Technical field

The present invention relates to a kind of method injecting produced quantity distribution for polymer flooding, belong to the technical field of polymer displacement of reservoir oil.

Background technology

Polymer displacement of reservoir oil tech adds polymer in displacing fluid, thus increase the viscosity of displacing fluid, suppresses the fingering of displacing fluid in oil reservoir, reach expansion swept volume, improves the object of recovery ratio.But in the waterflooding extraction process before polymer injection exploitation, inject water and make oil reservoir show serious non-homogeneity to washing away for a long time of high infiltration strip.If do not consider this non-homogeneity, then in polymer injection process, polymer, easily along high infiltration strip or macropore channelling, causes serious polymer waste, reduces the utilization rate of polymer.Therefore, suggestions for improvement, the key measure taked is carried out individual well exactly and is injected produced quantity distribution.

Current individual well injection produced quantity distributes to have received to be paid attention to widely.Wherein determine that the method for injection rate mainly contains individual well effective thickness method, voids volume computing method, individual well flattening-out Thickness Method etc., determine that the method for produced quantity mainly contains oil well fluid producing intensity method, well formation capacity splits point-score, oil-well strata coefficient analysis method etc.But these individual wells above inject method that produced quantity distributes or only considered single factors or artificial subjectivity is strong, and practical application coincidence rate is low, poor operability.Therefore, the polymer flooding individual well injection produced quantity distribution method setting up a set of comprehensive considering various effects is vital.

Summary of the invention

For the deficiencies in the prior art, the invention provides a kind of method injecting produced quantity distribution for polymer flooding.The method distributes the injection rate of each injection well by considering well group remaining geologic reserves and well group average moisture content, and considers the produced quantity dynamically associating coefficient and producing well individual well moisture content between injection-production well and distribute each producing well.

The method carries out the note amount of adopting for the individual well that non-homogeneity is strong, exploit uneven polymer flooding oil field to distribute, and the reasonable development for polymer flooding oil field provides good technical support.The present invention not only solves polymer solution in polymer flooding process and advances uneven problem, also improves the effective rate of utilization of polymer solution, suggestions for improvement.

Technical scheme of the present invention is as follows:

Inject a method for produced quantity distribution for polymer flooding, comprise step as follows:

(1) Injection Well in block and producing well are divided into different well group, the day injection of polymer total amount and day extraction total amount of record block; Record: the moisture content of injection rate in same time section of each Injection Well, producing well and produced quantity, the remaining geologic reserves of each well group, each producing well, the average moisture content of each well group and the average moisture content of block in block:

(2) the polymer injection rate of each well group in calculation block

I () is based on the polymer injection rate of each well group in the remaining geologic reserves calculation block of each well group for:

$Q_{\mathrm{im}}^1=\frac{N_m}{N_t}\×Q_{\mathrm{it}}---\left(I\right)$

In formula (I), N _tfor total surplus oil in place in block, 10 ⁴t; N _mbe the remaining geologic reserves of m well group, 10 ⁴t; Well group code name in m block, m is natural number; Q _itfor the total amount to injection of polymer in block, m ³/ d;

(ii) the polymer injection rate of each well group in the block calculated based on the average moisture content of each well group for:

$Q_{\mathrm{im}}^2=\frac{\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}\×Q_{\mathrm{it}}---\left(\mathrm{II}\right)$

In formula (II), for the average moisture content of block, %; f _wmbe the well group average moisture content of m well group, %; M is Injection Well sum in block, mouth; a ₁for the coefficient of deviation of well group moisture content, a ₁scope be 0 ~ 1, more close to 0, then individual-well injection rate is more close on average, and more close to 1, individual-well injection rate difference is larger;

(iii) the polymer injection rate Q of each well group in Method of Weighted Assignment Based calculation block is utilized _imfor:

$Q_{\mathrm{im}}={\mathrm{\α}}_1{Q}_{\mathrm{im}}^1+{\mathrm{\α}}_2{Q}_{\mathrm{im}}^2---\left(\mathrm{III}\right)$

In formula (III), α ₁, α ₂be respectively the remaining geologic reserves of each well group, the average moisture content of each well group injection of polymer gauge is calculated shared by weighted value, namely according to remaining geologic reserves and moisture content two factors, injection rate is distributed to the size of influence degree, preferably, described α ₁, α ₂get 0.7 and 0.3 respectively;

(3) produced quantity of each producing well in calculation block:

A) by balanced flood principle: the overall recovery Q of well group in described block _omequal the injection of polymer total amount of well group:

Q _om＝Q _im(IV)

B) according to injection rate in same time section of the Injection Well of record in step (1) and producing well and produced quantity data, calculate dynamic percent continuity between well, concrete computational process is see bibliography " wellblock, Junggar Basin land 9 J-2x-4 oil reservoir inter well connectivity " Du Qingjun etc., Xinjiang petroleum geology, 2010,31 (6): 621-623;

C) based on the produced quantity of each producing well of percent continuity calculating dynamic between well

$Q_{\mathrm{omn}}^1=\frac{\exp \left[a_2({\stackrel{\‾}{\mathrm{\α}}}_m-{\mathrm{\α}}_{\mathrm{mn}})\right]}{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\exp \left[a_2({\stackrel{\‾}{\mathrm{\α}}}_m-{\mathrm{\α}}_{\mathrm{mn}})\right]}\×Q_{\mathrm{om}}---\left(V\right)$

In formula (V), be the average of the dynamic percent continuity in m well group between Injection Well and all producing wells; α _mnit is the dynamic percent continuity in m mouth Injection Well and this well group between n-th mouthful of producing well; N is the sum of producing well in this well group, mouth; a ₂for the coefficient of deviation of dynamic percent continuity, a ₂scope be 0 ~ 1, more close to 0, then single well output is more close on average, and more close to 1, individual well Liquid output difference is larger;

The Liquid output of each producing well d) calculated based on the moisture content of producing well for:

$Q_{\mathrm{im}}^2=\frac{\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}\×Q_{\mathrm{it}}---\left(\mathrm{II}\right)$

In formula (VI), f _wmbe the average moisture content of all producing wells in m well group, %; f _wmnbe the moisture content of n-th mouthful of producing well in m well group, %; a ₃for controlling individual well moisture content difference to Influence on test result degree constant, a ₃scope be 0 ~ 1, more close to 0, then Liquid output is more close on average, and more close to 1, then Liquid output difference is larger; Preferably, described a ₃=0.2;

E) Method of Weighted Assignment Based is utilized to calculate the produced quantity of each producing well in well group

Consider the produced quantity Q of each producing well in step (c) and step (d) well group _oLfor:

$Q_{\mathrm{OL}}={\mathrm{\β}}_1{Q}_{\mathrm{omn}}^1+{\mathrm{\β}}_2{Q}_{\mathrm{omn}}^2---\left(\mathrm{VII}\right)$

In formula (VII), β ₁, β ₂be respectively based on percent continuity calculating dynamic between well, calculate gained produced quantity to the weighted value shared by actual output based on the moisture content of producing well; Weight shared by two factors.The size of influence degree is distributed to Liquid output, β according to percent continuity dynamic between well and moisture content two factors ₁, β ₂get 0.4 and 0.6 respectively;

F) the produced quantity sum that each well group of producing well belonging to it obtains is exactly the final produced quantity that this producing well distributes.

Advantage of the present invention is:

In the technical field of polymer displacement of reservoir oil, generally speaking, remaining geologic reserves is large, and the injection-production well group potentiality to be exploited that average moisture content is low is large, and the injection rate of distribution is large, otherwise the injection rate of then distributing is little; For producing well based on balanced flood principle, the produced quantity that between well, the little and producing well that moisture content is low of channelling degree distributes is large, otherwise the produced quantity then distributed is little.The present invention distributes the injection rate of each injection well by considering well group remaining geologic reserves and well group average moisture content, consider dynamic percent continuity and producing well individual well moisture content between injection-production well and distribute the Liquid output of each producing well, the method is qualitative objective, workable, the distribution that can be polymer flooding individual well injection produced quantity provides technical support.

Attached caption

Fig. 1 is the flow chart of distribution method of the present invention;

Fig. 2 is each well location schematic diagram in block;

Fig. 3 is the block diagram that in block, each well group polymer injection rate is distributed;

Fig. 4 is the block diagram that in block, each producing well produced quantity distributes.

Detailed description of the invention

Now for manual and Figure of description, the present invention is described in detail, but is not limited thereto.

Embodiment,

Inject for polymer flooding the method that produced quantity distributes, wherein, involved block makes reservoir parameter have a very large change due to the waterflooding extraction of long period in advance, exacerbates the non-homogeneity of reservoir.Transfer to polymer flooding exploitation after in order to make polymer solution evenly advance towards producing well, improve its effective rate of utilization, need carry out individual well inject produced quantity distribute.

3 mouthfuls of Injection Wells, 11 mouthfuls of producing wells are comprised, as shown in Figure 2 in block.

In block, injection rate is 0.1PV/a, day polymer waterflooding be 440m ³/ d, day produced quantity be 440m ³/ d.The remaining geologic reserves of each well group, between the moisture content of each producing well and well dynamically percent continuity in table 1:

Table 1

Inject a method for produced quantity distribution for polymer flooding, comprise step as follows:

(1) Injection Well in block and producing well are divided into different well group, the day injection of polymer total amount and day extraction total amount of record block; Record: the moisture content of injection rate in same time section of each Injection Well, producing well and produced quantity, the remaining geologic reserves of each well group, each producing well, the average moisture content of each well group and the average moisture content of block in block:

(2) the polymer injection rate of each well group in calculation block

I () is based on the polymer injection rate of each well group in the remaining geologic reserves calculation block of each well group for:

$Q_{\mathrm{im}}^1=\frac{N_m}{N_t}\×Q_{\mathrm{it}}---\left(I\right)$

In formula (I), N _tfor total surplus oil in place in block, 10 ⁴t; N _mbe the remaining geologic reserves of m well group, 10 ⁴t; Well group code name in m block, m is natural number; Q _itfor the total amount to injection of polymer in block, m ³/ d;

(ii) the polymer injection rate of each well group in the block calculated based on the average moisture content of each well group for:

$Q_{\mathrm{im}}^2=\frac{\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}\×Q_{\mathrm{it}}---\left(\mathrm{II}\right)$

In formula (II), for the average moisture content of block, %; f _wmbe the well group average moisture content of m well group, %; M is Injection Well sum in block, mouth; a ₁for the coefficient of deviation of well group moisture content, a ₁scope be 0 ~ 1, more close to 0, then individual-well injection rate is more close on average, and more close to 1, individual-well injection rate difference is larger;

(iii) the polymer injection rate Q of each well group in Method of Weighted Assignment Based calculation block is utilized _imfor:

$Q_{\mathrm{im}}={\mathrm{\α}}_1{Q}_{\mathrm{im}}^1+{\mathrm{\α}}_2{Q}_{\mathrm{im}}^2---\left(\mathrm{III}\right)$

In formula (III), α ₁, α ₂be respectively the remaining geologic reserves of each well group, the average moisture content of each well group injection of polymer gauge is calculated shared by weighted value, namely according to remaining geologic reserves and moisture content two factors, injection rate is distributed to the size of influence degree, preferably, described α ₁, α ₂get 0.7 and 0.3 respectively;

For well group belonging to Injection Well I5-21, the process determining Injection Well injection rate is described.

First as shown in Table 1 the remaining geologic reserves of this well group is 17.41 × 10 ⁴t, the total surplus oil in place of block is the remaining geologic reserves sum of each well group, is 60.83 × 10 ⁴t, then the injection rate determined by remaining geologic reserves is 126m ³/ d; The block average moisture content obtained by the moisture content of producing wells all in block is 93.69%, and the average moisture content obtaining again this well group is 94.07%, a ₁get 0.1, then the injection rate determined by moisture content is 146.53m ³/ d; According to the two weight calculation consider dual factors time final injection rate be 126 × 0.7+146.53 × 0.3=132.20m ³/ d.Repeat the injection rate that this process can determine all Injection Wells in block, see Fig. 3.

(3) produced quantity of each producing well in calculation block:

A) by balanced flood principle: the total fluid production Q of well group in described block _omequal the injection of polymer total amount of well group:

Q _om＝Q _im(IV)

B) according to injection rate in same time section of the Injection Well of record in step (1) and producing well and produced quantity data, calculate dynamic percent continuity between well, concrete computational process is see bibliography " wellblock, Junggar Basin land 9 J-2x-4 oil reservoir inter well connectivity " Du Qingjun etc., Xinjiang petroleum geology, 2010,31 (6): 621-623;

C) based on the Liquid output of each producing well of percent continuity calculating dynamic between well

$Q_{\mathrm{omn}}^1=\frac{\exp \left[a_2({\stackrel{\‾}{\mathrm{\α}}}_m-{\mathrm{\α}}_{\mathrm{mn}})\right]}{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\exp \left[a_2({\stackrel{\‾}{\mathrm{\α}}}_m-{\mathrm{\α}}_{\mathrm{mn}})\right]}\×Q_{\mathrm{om}}---\left(V\right)$

In formula (V), be the average of the dynamic percent continuity in m well group between Injection Well and all producing wells; α _mnit is the dynamic percent continuity in m mouth Injection Well and this well group between n-th mouthful of producing well; N is the sum of producing well in this well group, mouth; a ₂for the coefficient of deviation of dynamic percent continuity, a ₂scope be 0 ~ 1, more close to 0, then individual well Liquid output is more close on average, and more close to 1, individual well Liquid output difference is larger;

The Liquid output of each producing well d) calculated based on the moisture content of producing well for:

$Q_{\mathrm{im}}^2=\frac{\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}\×Q_{\mathrm{it}}---\left(\mathrm{II}\right)$

In formula (VI), f _wmbe the average moisture content of all producing wells in m well group, %; f _wmnbe the moisture content of n-th mouthful of producing well in m well group, %; a ₃for controlling individual well moisture content difference to Influence on test result degree constant, a ₃scope be 0 ~ 1, more close to 0, then produced quantity is more close on average, and more close to 1, then produced quantity difference is larger; Preferably, described a ₃=0.2;

E) Method of Weighted Assignment Based is utilized to calculate the produced quantity of each producing well in well group

Consider the produced quantity Q of each producing well in step (c) and step (d) well group _oLfor:

$Q_{\mathrm{OL}}={\mathrm{\β}}_1{Q}_{\mathrm{omn}}^1+{\mathrm{\β}}_2{Q}_{\mathrm{omn}}^2---\left(\mathrm{VII}\right)$

In formula (VII), β ₁, β ₂be respectively based on percent continuity calculating dynamic between well, calculate gained produced quantity to the weighted value shared by actual output based on the moisture content of producing well; Weight shared by two factors.The size of influence degree is distributed to Liquid output, β according to percent continuity dynamic between well and moisture content two factors ₁, β ₂get 0.4 and 0.6 respectively;

F) the produced quantity sum that each well group of producing well belonging to it obtains is exactly the final produced quantity that this producing well distributes.

What for producing well S5-238 producing well is described joins product process:

Two well groups comprise this producing well as shown in Figure 2, are well group I5-21 and well group I5-234 respectively.The injection rate that these two well groups distribute as shown in Figure 3 is respectively 132.20m ³/ d and 136.45m ³/ d, thus by balanced flood principle obtain two well groups distribute overall recovery be respectively 132.20m ³/ d and 136.45m ³/ d.

For well group I5-21, be 0.0422, a according to the table 1 dynamic percent continuity that can obtain between I5-21 and S5-238 ₂get 0.7, then the produced quantity of the producing well S5-328 determined by dynamic percent continuity is 31.44m ³/ d; The moisture content of all producing wells in this well group as shown in Table 1, trying to achieve well group moisture content is 94.07%, a ₃get 0.2, then the produced quantity of the producing well S5-238 determined by moisture content is 26.28m ³/ d; According to the two weight calculation obtain consider dual factors time produced quantity be 31.44 × 0.4+26.28 × 0.6=28.34m ³/ d.

The produced quantity that same process obtains producing well S5-238 in well group I5-234 is 18.93m ³/ d, the final produced quantity that so producing well S5-238 distributes is the produced quantity sum that it obtains from two affiliated well groups, i.e. 28.34+18.93=47.27m ³/ d.

Identical process obtains the produced quantity that all producing wells in trial zone distribute, as shown in Figure 4.

Before the contrast individual well note amount of adopting allocation optimized with optimize after polymer flooding development effectiveness, prioritization scheme is not low by 1.72% at polymer flooding initial stage moisture content ratio for prioritization scheme, prioritization scheme is not high by 1.15% for ultimate recovery ratio, as seen the method Be very effective distributed for the polymer flooding individual well note amount of adopting provided by the invention.

Claims (1)

1. inject a method for produced quantity distribution for polymer flooding, it is characterized in that, it is as follows that the method comprising the steps of:

(1) Injection Well in block and producing well are divided into different well group, the day injection of polymer total amount and day extraction total amount of record block; Record: the moisture content of injection rate in same time section of each Injection Well, producing well and produced quantity, the remaining geologic reserves of each well group, each producing well, the average moisture content of each well group and the average moisture content of block in block:

(2) the polymer injection rate of each well group in calculation block

I () is based on the polymer injection rate of each well group in the remaining geologic reserves calculation block of each well group for:

$Q_{\mathrm{im}}^1=\frac{N_m}{N_t}\×Q_{\mathrm{it}}---\left(I\right)$

In formula (I), N _tfor total surplus oil in place in block, 10 ⁴t; N _mbe the remaining geologic reserves of m well group, 10 ⁴t; Well group code name in m block, m is natural number; Q _itfor the total amount to injection of polymer in block, m ³/ d;

(ii) the polymer injection rate of each well group in the block calculated based on the average moisture content of each well group for:

$Q_{\mathrm{im}}^2=\frac{\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}{\underset{m=1}{\overset{M}{\mathrm{\Σ}}}\exp \left[a_1({\stackrel{\‾}{f}}_w-f_{\mathrm{wm}})\right]}\×Q_{\mathrm{it}}---\left(\mathrm{II}\right)$

In formula (II), for the average moisture content of block, %; f _wmbe the well group average moisture content of m well group, %; M is Injection Well sum in block, mouth; a ₁for the coefficient of deviation of well group moisture content, a ₁scope be 0 ~ 1, more close to 0, then individual-well injection rate is more close on average, and more close to 1, individual-well injection rate difference is larger;

(iii) the polymer injection rate Q of each well group in Method of Weighted Assignment Based calculation block is utilized _imfor:

$Q_{\mathrm{im}}={\mathrm{\α}}_1{Q}_{\mathrm{im}}^1+{\mathrm{\α}}_2{Q}_{\mathrm{im}}^2---\left(\mathrm{III}\right)$

In formula (III), α ₁, α ₂be respectively the remaining geologic reserves of each well group, the average moisture content of each well group injection of polymer gauge is calculated shared by weighted value, namely according to remaining geologic reserves and moisture content two factors, injection rate is distributed to the size of influence degree, preferably, described α ₁, α ₂get 0.7 and 0.3 respectively;

(3) produced quantity of each producing well in calculation block:

A) by balanced flood principle: the overall recovery Q of well group in described block _omequal the injection of polymer total amount of well group:

Q _om＝Q _im(IV)

B) according to injection rate in same time section of the Injection Well of record in step (1) and producing well and produced quantity data, calculate dynamic percent continuity between well, concrete computational process is see bibliography " wellblock, Junggar Basin land 9 J-2x-4 oil reservoir inter well connectivity " Du Qingjun etc., Xinjiang petroleum geology, 2010,31 (6): 621-623;

C) based on the produced quantity of each producing well of percent continuity calculating dynamic between well

$Q_{\mathrm{omn}}^1=\frac{\exp \left[a_2({\stackrel{\‾}{\mathrm{\α}}}_m-{\mathrm{\α}}_{\mathrm{mn}})\right]}{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\exp \left[a_2({\stackrel{\‾}{\mathrm{\α}}}_m-{\mathrm{\α}}_{\mathrm{mn}})\right]}\×Q_{\mathrm{om}}---\left(V\right)$

In formula (V), be the average of the dynamic percent continuity in m well group between Injection Well and all producing wells; α _mnit is the dynamic percent continuity in m mouth Injection Well and this well group between n-th mouthful of producing well; N is the sum of producing well in this well group, mouth; a ₂for the coefficient of deviation of dynamic percent continuity, a ₂scope be 0 ~ 1, more close to 0, then single well output is more close on average, and more close to 1, individual well Liquid output difference is larger;

The Liquid output of each producing well d) calculated based on the moisture content of producing well for:

$Q_{\mathrm{omn}}^2=\frac{\exp \left[a_3\left({\stackrel{\‾}{\mathrm{f\α}}}_{\mathrm{wm}}{-\mathrm{f\α}}_{\mathrm{wmn}}\right)\right]}{\underset{n=1}{\overset{N}{\mathrm{\Σ}}}\exp \left[a_3({\stackrel{\‾}{f}}_{\mathrm{wm}}-f_{\mathrm{wmn}})\right]}\×Q_{\mathrm{om}}---\left(\mathrm{VI}\right)$

In formula (VI), f _wmbe the average moisture content of all producing wells in m well group, %; f _wmnbe the moisture content of n-th mouthful of producing well in m well group, %; a ₃for controlling individual well moisture content difference to Influence on test result degree constant, a ₃scope be 0 ~ 1, more close to 0, then Liquid output is more close on average, and more close to 1, then Liquid output difference is larger; Preferably, described a ₃=0.2;

E) Method of Weighted Assignment Based is utilized to calculate the produced quantity of each producing well in well group

Consider the produced quantity Q of each producing well in step (c) and step (d) well group _oLfor:

$Q_{\mathrm{OL}}={\mathrm{\β}}_1{Q}_{\mathrm{omn}}^1+{\mathrm{\β}}_2{Q}_{\mathrm{omn}}^2---\left(\mathrm{VII}\right)$

In formula (VII), β ₁, β ₂be respectively based on percent continuity calculating dynamic between well, calculate gained produced quantity to the weighted value shared by actual output based on the moisture content of producing well; β ₁, β ₂get 0.4 and 0.6 respectively;

F) the produced quantity sum that each well group of producing well belonging to it obtains is exactly the final produced quantity that this producing well distributes.