CN106150463A - A kind of Conglomerate Reservoir polymer flooding injection pressure increasing degree determines method - Google Patents

Abstract

Invention provides a kind of Conglomerate Reservoir polymer flooding injection pressure increasing degree and determines method, comprises the following steps: (a) gathers injection well group core intersection h, injector producer distance r, wellbore radius r_w, note poly-viscosity, mu and injection rate q；B () calculates mean permeability k:k is that injection well group injects well and extraction well permeability k_iMeansigma methods；C (), according to the mean permeability k obtained in step (a), calculates coefficient T of averagely advancing by leaps and bounds_k, coefficient T of averagely advancing by leaps and bounds_kIt is that injection well group is injected well and extraction well and advanced by leaps and bounds the meansigma methods of coefficient；D () calculates maximum injection pressure increasing degree Δ P_max.Conglomerate Reservoir polymer flooding injection pressure increasing degree of the present invention determines method, clear principle, quantification, workable, it is easy to use, decrease and determined injection parameter by on-the-spot injection test in the past, solve Conglomerate Reservoir difference well group and use differentiation injection parameter, be greatly improved timeliness, saved cost.

Description

A kind of Conglomerate Reservoir polymer flooding injection pressure increasing degree determines method

Technical field

The invention belongs to oil development reservoir engineering technical field, especially relate to a kind of Conglomerate Reservoir polymer flooding and inject Pressure increasing degree determines method.

Background technology

Improve oil recovery factor and become countries in the world question of common concern.Along with the industrialized popularization of polymer flooding should With, it is the most undeniable that polymer solution can significantly increase oil recovery factor.The ultimate principle of polymer displacement of reservoir oil is by increasing The viscosity of displacing phase, improves oil and water mobility ratio, utilizes polymer to reduce the permeability injecting well high permeability formation, thus expands and involve body Long-pending, and then improve oil displacement efficiency.Injection pressure calculating is the pith of polymer displacement of reservoir oil parameter designing, is polymerized rational Thing Drainage process is significant.

The principal element affecting polymer flooding injection pressure has reservoir property, injector producer distance, injection rate, injected media Deng.The quality of reservoir geology condition is the key factor affecting the change of polymer flooding injection pressure, and formation capacity is the least, in oil reservoir The filtrational resistance of fluid is the biggest, and injection pressure ascensional range is the biggest, and vice versa；The rising value of polymer flooding injection pressure The manyfold bigger than quadratic relationship with the relation of injector producer distance, therefore the change of injector producer distance is on injection pressure impact maximum, Its reason is that injector producer distance is the biggest, and the irritability between injection-production well is the poorest, and polymer drives the most difficult；Polymer flooding mobility The least, injection pressure rising value is the biggest, and its mobility is relevant with polymer viscosity, and polymer molecular weight is the biggest, and viscosity is more Greatly, (implantation concentration is the highest, and its viscosity is the biggest), its absorption in oil reservoir, trapping are the most, and reservoir permeability declines to be got over Greatly, injection pressure rises the biggest.Polymer flooding injection pressure and its injection rate are directly proportional, because injection rate is the biggest, and note Enter resistance the biggest；Polymer flooding injection pressure is directly proportional to injecting intensity, because it is the biggest to inject intensity, filtrational resistance is the biggest, from And injection pressure is the biggest.During polymer flooding, the injection pressure initial stage rate of climb is fast, but after injecting a period of time, injects Pressure level-off and steadily increasing, notes the normal variation of poly-pressure when this is polymer flooding；But, and the note of not all well is poly- Pressure all follows such rule, and the oil increasing effect of polymer flooding is also not quite similar.Injection pressure rises too fast, on the one hand easily makes Becoming injection-production ratio to increase, inject difficulty, on the other hand strata pressure rapid increase, producing pressure differential increases, makes injection of polymer solution Along microcrack, layer reason channelling, cause Liquid output to decline, produce poly-concentration and rise.Injection pressure rose slowly, failed to change former seepage flow Path, expands and involves scope, cause the inefficient of polymer solution to circulate.

Injection pressure in note collecting process rises, and can describe with the change of Hall Curve slope, applies Hall Curve Slope calculates apparent resistance factor.The rational resistance coefficient of middle and high infiltration sandstone is about 2.2, and resistance coefficient is too big, illustrates to inject pressure Power rises fast, and contrary resistance coefficient is the least, illustrates that injection pressure rises slow.

" area north, Fructus Pruni north 4～6 block notes poly-initial stage pressure increasing degree law study " that Chen Yongda etc. deliver uses seepage force Gain knowledge and carry out deriving analysis, it may be determined that pressure increasing degree and maximum pressure increasing degree in note collecting process, but the method is based on homogenizing Model, there is certain difference in result of calculation and actual production.

Conglomerate Reservoir has in the deposition characteristics different from conventional sandstone reservoir, complicated pore structure and plane and hangs down Heterogeneous reservoirs on section, brings great difficulty to the exploitation of Conglomerate Reservoir.At present, Conglomerate Reservoir polymer flooding note Enter pressure and be only limitted to qualitative description, and the increasing degree of pressure after well group injection of polymer solution can not be predicted.Owing to Conglomerate Reservoir stores up Layer anisotropism is strong, and each well group uses identical injection parameter and system pressure increasing degree to differ greatly, and has a strong impact on oil increasing effect.

Summary of the invention

For above-mentioned technical problem, it is an object of the invention to provide a kind of Conglomerate Reservoir polymer flooding injection pressure increasing degree Determine method, with solve in process of polymer flooding development pressure increasing degree cannot Accurate Prediction, the blindness that injection parameter adjusts is asked Topic, optimizes for polymer flooding injection parameter, and Efficient Development provides strong technical support.

The technical solution used in the present invention is:

A kind of Conglomerate Reservoir polymer flooding injection pressure increasing degree determines method, comprises the following steps:

A () gathers injection well group core intersection h, injector producer distance r, wellbore radius r_w, note poly-viscosity, mu and injection rate q；

B () calculates mean permeability k:k is that injection well group injects well and the meansigma methods of extraction well permeability；

C (), according to the mean permeability k obtained in step (a), calculates coefficient T of averagely advancing by leaps and bounds_k, coefficient T of averagely advancing by leaps and bounds_kIt is Injection well group is injected well and extraction well and is advanced by leaps and bounds the meansigma methods of coefficient；

D () calculates maximum injection pressure increasing degree Δ P_max: above parameter is substituted into formula (3), i.e. can obtain injecting the maximum of well Injection pressure increasing degree,

${\mathrm{\ΔP}}_{max}=0.16T_k\frac{q\mathrm{\μ}}{kh}\ln \frac{r}{r_w}---\left(3\right)$

Wherein, q is diurnal injection；μ is the viscosity of injected media；T_kFor coefficient of averagely advancing by leaps and bounds；H is core intersection；r_wFor well Cylinder radius；K is mean permeability；R is injector producer distance.

Conglomerate Reservoir polymer flooding injection pressure increasing degree of the present invention determines method, and wherein, (1) calculates step as the following formula Suddenly mean permeability k described in (b)；

$k=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_i---\left(1\right)$

Wherein, k_iWell and extraction well permeability is injected for injection well group.

Conglomerate Reservoir polymer flooding injection pressure increasing degree of the present invention determines method, and wherein, (2) calculate step as the following formula Suddenly averagely advance by leaps and bounds described in (c) coefficient T_k；

$T_k=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_{\max i}/k_i---\left(2\right)$

Wherein, k_maxiWell and extraction well maximum permeability is injected for injection well group.

The method have the benefit that

Conglomerate Reservoir polymer flooding injection pressure increasing degree of the present invention determines method, the method application oil reservoir (well group) Static reservoir properties, core intersection, coefficient of advancing by leaps and bounds, injector producer distance, Dynamic injection speed and polymer viscosity parameter can be really Determine injection pressure biggest advance, the inventive method clear principle, quantification, workable, it is simple to use, join for polymer flooding Number optimizes, and on-the-spot tracking adjustment provides reliable foundation；The present invention has filled up Conglomerate Reservoir polymer flooding injection pressure increasing degree The blank quantitatively determined, decreases and determined injection parameter by on-the-spot injection test in the past, solve Conglomerate Reservoir difference well group and adopt Use differentiation injection parameter, be greatly improved timeliness, save cost.

Detailed description of the invention

The present embodiment, as a example by the eastern 1st district polymer flooding test in Karamay Oil Fields in Xinjiang seven, injects polymerization in JIUYUE, 2006 Thing solution, terminates, utilize the present embodiment method to determine maximum pressure increasing degree, instruct polymer injection parameter optimization in October, 2012, gathers and drives Development effectiveness is preferable.Trial zone accumulation volume increase 17.4 ten thousand tons, stage recovery percent of reserves 9.0%, compared with water drive end, moisture content by 94.5% drops to 67.5%, and rate of oil production is brought up to 3.9% by 0.5%.

The present embodiment one Conglomerate Reservoir polymer flooding injection pressure increasing degree determines method, comprises the following steps:

A () gathers injection well group core intersection h, injector producer distance r, wellbore radius r_w, note poly-viscosity, mu and injection rate q, adopt Collection parameter is as shown in table 1；

B () calculates mean permeability k:k according to following formula (1) is that injection well group injects well and extraction well permeability k_iFlat Average, permeability k_iSupplemental characteristic is as shown in table 2, and mean permeability k result of calculation is as shown in table 3；

$k=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_i---\left(1\right)$

C (), according to the mean permeability k obtained in step (a), (2) calculate coefficient T of averagely advancing by leaps and bounds as the following formula_k: the most prominent Enter coefficient T_kIt is that injection well group is injected well and extraction well and advanced by leaps and bounds the meansigma methods of coefficient, wherein, k_maxiInject well for injection well group and adopt Go out well maximum permeability, k_maxiSupplemental characteristic is as shown in table 4, coefficient T of averagely advancing by leaps and bounds_kResult of calculation is as shown in table 5；

$T_k=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_{\max i}/k_i---\left(2\right)$

D () calculates maximum injection pressure increasing degree Δ P_max: above parameter is substituted into formula (3), i.e. can obtain injecting the maximum of well Injection pressure increasing degree, Δ P_maxResult of calculation is as shown in table 6,

${\mathrm{\ΔP}}_{max}=0.16T_k\frac{q\mathrm{\μ}}{kh}\ln \frac{r}{r_w}---\left(3\right)$

Wherein, q is diurnal injection, m³/d；μ is the viscosity of injected media, mPa.s；Tk is coefficient of averagely advancing by leaps and bounds；H is oil Layer thickness, m；r_wFor wellbore radius, m；K is mean permeability, mD；R is injector producer distance, m.

Table 1 In Karamay Oil Radix Notoginseng east 1 polymer flooding trial zone, district parameter acquisition table

Table 2 In Karamay Oil Radix Notoginseng east 1 polymer flooding trial zone, district Permeability Parameters tables of data

Table 3 In Karamay Oil Radix Notoginseng east 1 polymer flooding trial zone, district mean permeability result of calculation

Advance by leaps and bounds coefficient data table in 1 polymer flooding trial zone, district, table 4 In Karamay Oil Radix Notoginseng east

Averagely advance by leaps and bounds coefficient calculations result in 1 polymer flooding trial zone, district, table 5 In Karamay Oil Radix Notoginseng east

Table 6 In Karamay Oil Radix Notoginseng east 1 polymer flooding trial zone, district maximum injection pressure increasing degree result of calculation

Embodiment described above is only to be described the preferred embodiment of the present invention, the not model to the present invention Enclose and be defined, on the premise of designing spirit without departing from the present invention, the those of ordinary skill in the art technical side to the present invention Various deformation that case is made and improvement, all should fall in the protection domain that claims of the present invention determines.

Claims (3)

1. a Conglomerate Reservoir polymer flooding injection pressure increasing degree determines method, it is characterised in that: comprise the following steps:

A () gathers injection well group core intersection h, injector producer distance r, wellbore radius r_w, note poly-viscosity, mu and injection rate q；

B () calculates mean permeability k:k is that injection well group injects well and the meansigma methods of extraction well permeability；

C (), according to the mean permeability k obtained in step (a), calculates coefficient T of averagely advancing by leaps and bounds_k, coefficient T of averagely advancing by leaps and bounds_kIt is that note is poly- Well group injects well and extraction well and advances by leaps and bounds the meansigma methods of coefficient；

D () calculates maximum injection pressure increasing degree Δ P_max: above parameter is substituted into formula (3), i.e. can obtain injecting the maximum injection of well Pressure increasing degree,

${\mathrm{\ΔP}}_{max}=0.16T_k\frac{q\mathrm{\μ}}{kh}\ln \frac{r}{r_w}---\left(3\right)$

Wherein, q is diurnal injection；μ is the viscosity of injected media；T_kFor coefficient of averagely advancing by leaps and bounds；H is core intersection；r_wFor pit shaft half Footpath；K is mean permeability；R is injector producer distance.

Conglomerate Reservoir polymer flooding injection pressure increasing degree the most according to claim 1 determines method, it is characterised in that: press Mean permeability k described in formula (1) calculation procedure (b)；

$k=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_i---\left(1\right)$

Wherein, k_iWell and extraction well permeability is injected for injection well group.

Conglomerate Reservoir polymer flooding injection pressure increasing degree the most according to claim 1 and 2 determines method, it is characterised in that: Averagely advance by leaps and bounds described in (2) calculation procedure (c) as the following formula coefficient T_k；Wherein, k_maxiInject well for injection well group and extraction well is maximum Permeability；

$T_k=\frac{1}{n}\underset{i=1}{\overset{n}{\mathrm{\Σ}}}{k}_{\max i}/k_i---\left(2\right)$

Wherein, k_maxiWell and extraction well maximum permeability is injected for injection well group.