CN103939066B - An a kind of note adopts the method that well group determines water injection rate determination oilwell produced fluid amount more - Google Patents

Abstract

The present invention relates to and realize at utmost equilibrium displacement in the plane for waterflooding reservoir and provide an a kind of note to adopt the method that well group determines water injection rate determination oilwell produced fluid amount more, the method comprises: step 1, note is adopted control area and to be split point and parameter equivalent process, and an actual note being adopted more well group equivalent process is that a note one of multiple one-dimensional linear displacement adopts unit; Step 2, a given water breakthrough time, calculates the Liquid output of each flooding unit oil well; Step 3, according to the well water injection rate that oil field actual conditions are determined, judges that whether oilwell produced fluid amount sum is equal with well water injection rate, as equal, the then reasonable liquid measure of Liquid output now and each oil well, as unequal, changing the water breakthrough time recalculates each oilwell produced fluid amount; Step 4, according to the reasonable Liquid output of each oil well determined, adjusts the working system of each pumping unit of well at mining site, each oil well is produced according to the reasonable Liquid output determined.

Description

An a kind of note adopts the method that well group determines water injection rate determination oilwell produced fluid amount more

Technical field

The present invention relates to waterflooding reservoir structure adjusting technical field, particularly relate to an a kind of note based at utmost equilibrium displacement and adopt the method that well group determines the reasonable Liquid output of water injection rate determination oil well more.In addition, the invention still further relates to a kind of oil production method, comprise the Liquid output being set as by the Liquid output of oil well being obtained by said method.

Background technology

Fault block oil reservoir is the class oil reservoir occupying critical role in China's oil field development.In many garden basin oil reservoirs of east China, fault block oil reservoir is occupied an leading position.Due to fault block oil reservoir complex structure, mature fault, reservoir heterogeneity is serious and stratigraphic dip is comparatively large, and these features will cause fault block oil reservoir plane water drive situation when carrying out waterflooding extraction seriously unbalanced.For the fault block oil reservoir that well pattern has been fixed, through long-term waterflooding extraction, its streamline is also substantially fixing, and the impact scope injecting water is limited; Meanwhile, by beating new well, to carry out the economic benefit of well pattern thickening poor in development late stage for fault block oil reservoir, and do not need extra input just can obtain higher oil production and economic benefit to the adjustment that oil well carries out Liquid output.Therefore, carrying out liquid measure adjustment to oil well is cost-effective important measures.In actual oil recovery process, determine that the reasonable liquid measure of oil well is very important for changing original grain direction, expanding original streamline impact scope, effectively improve waterflooding development effect and finally realize equilibrium displacement.Simultaneously by determining the rational Liquid output of oil well, effectively can reduce moisture content, increasing well oil output, improve recovery ratio, make oil field obtain maximum economic benefit.

Summary of the invention

The object of this invention is to provide a kind of method that can realize waterflooding extraction fault block oil reservoir at utmost equilibrium displacement in the plane, namely a note adopts the method that well group determines water injection rate determination oilwell produced fluid amount more.

The present invention can be achieved by the following technical measures:

(1). note is adopted control area and to be split point and parameter equivalent process, and an actual note being adopted more well group equivalent process is that multiple one-dimensional linear displacement one note one adopts unit;

(2). a given water breakthrough time, calculate the Liquid output of each flooding unit oil well; Here propose to adopt iterative method to calculate the Liquid output of each flooding unit oil well: first suppose that an oilwell produced fluid amount is Q ₁, adopt Q ₁value calculates moisture content and corresponding leading edge water saturation, then tries to achieve oilwell produced fluid amount Q according to leading edge water saturation and given water breakthrough time ₂; Finally, the assumed value Q of oilwell produced fluid amount is judged ₁with calculated value Q ₂whether equal, as equal, just can obtain the Liquid output of oil well under this water breakthrough time, as unequal, again suppose that the Liquid output of oil well carries out calculating till equal.

(3). according to the well water injection rate that oil field actual conditions are determined, judge that whether oilwell produced fluid amount sum is equal with well water injection rate, as equal, then the reasonable liquid measure of Liquid output now and oil well, as unequal, changing the water breakthrough time recalculates oilwell produced fluid amount till equal.

Key technology main points comprise:

1. note is adopted control area and to be split point and parameter equivalent process

1.1 notes are adopted control area and to be split point

An actual note n being adopted well group division is that a n note one adopts unit, and the control area that each note one adopts unit gets the area surrounded between the angular bisector of adjacent two pairs of producing wells line separately and between water injection well; After each control area is determined, each note one is adopted unit and be reduced to the ribbon one-dimensional linear displacement model adopted along each note on line direction, the length of this one-dimensional linear displacement model is the distance between injection-production well, wide is the control area of corresponding flooding unit and the ratio of injector producer distance, thus the control area that the note one before guarantee simplification adopts unit and the one-dimensional linear displacement model after simplifying is equal.

For Five-point method pattern, as shown in Figure 1, an actual note being adopted more well group division is that four notes one adopt unit.In figure, P1, P2, P3 and P4 are producing well, I is water injection well, the note one formed for producing well P2 and water injection well I is adopted unit and the concrete steps of splitting point control area is described: first, make producing well P2 and the line between adjacent two mouthfuls of producing wells P1, P3 and well I thereof, come to 3, be respectively line P2I, P1I and P3I; Secondly, make the angular bisector of angle and angle ∠ P1IP2 and ∠ P2IP3 between these 3 lines, come to 2, i.e. line P ' I and P " I; Finally, make producing well P2 and the line between oil well P1, P3, come to 2, the quadrangle P ' P2P that they and 2 angular bisectors surround " area of I is the control area A that a note one that producing well P2 and water injection well I forms adopts unit.

1.2 parameter equivalent process

The note one formed for producing well P2 and water injection well I equally adopts unit, after splitting point complete control area, this flooding unit is reduced to an one-dimensional linear displacement model, the length L of this model is the distance between producing well P2 and water injection well I, its width B is the control area A of corresponding flooding unit and the ratio of injector producer distance L, and the parameters such as its thickness h, degree of porosity φ, permeability k get the weighted average of relevant parameter in flooding unit with calculate in the following several ways:

(1) distribution function h (x, y), the φ (x, y, z) of each parameter, k (x, y, z) in known formation:

$\stackrel{\‾}{h}=\frac{1}{A}\underset{A}{\∫\∫}h(x,y)\mathrm{dxdy}$

$\stackrel{\‾}{\mathrm{\φ}}=\frac{1}{V}\underset{V}{\∫\∫\∫}\mathrm{\φ}(x,y,z)\mathrm{dxdydz}$

$\stackrel{\‾}{k}=\frac{1}{V}\underset{V}{\∫\∫\∫}k(x,y,z)\mathrm{dxdydz}$

(2) distribution function h (x, y), φ (x, y), the k (x, y) of each parameter on known injection-production well line:

$\stackrel{\‾}{h}=\frac{1}{L}\underset{l}{\∫}h(x,y)\mathrm{ds}$

$\stackrel{\‾}{\mathrm{\φ}}=\frac{1}{L}\underset{l}{\∫}\mathrm{\φ}(x,y)\mathrm{ds}$

$\stackrel{\‾}{k}=\frac{1}{L}\underset{l}{\∫}k(x,y)\mathrm{ds}$

(3) parameter value at known each injection-production well well point place:

$\stackrel{\‾}{h}=\left(h_o{+h}_w\right)/2$

$\stackrel{\‾}{\mathrm{\φ}}=({\mathrm{\φ}}_o{h}_o+{\mathrm{\φ}}_w{h}_w)/(h_o+h_w)$

$\stackrel{\‾}{k}=(k_o{h}_o+k_w{h}_w)/(h_o+h_w)$

Wherein, h _oand h _wbe respectively the core intersection of producing well, location, water filling well point layer; φ _oand φ _wbe respectively the degree of porosity of producing well, location, water filling well point layer; k _oand k _wbe respectively the permeability of producing well, location, water filling well point layer.A is the area of flooding unit, and V is the volume of flooding unit, and x, y, z is the position coordinates of any point.In this article, except as otherwise noted, subscript o represents producing well, and subscript w represents water injection well.

2. iterative method calculates the Liquid output determining oil well under the water breakthrough time

A given water breakthrough time T, adopt iterative method to try to achieve the Liquid output of each flooding unit oil well, the concrete implementation step of iterative method is as follows:

First, assuming that oilwell produced fluid amount is Q ₁, according to the design formulas of moisture content (wherein, μ _ofor viscosity of crude, μ _wfor formation water viscosity; k _ro, k _rwbe respectively the relative permeability of oil phase and aqueous phase, its numerical value can be obtained according to the permeability saturation curve in oil field) and the change curve f of moisture content with water saturation can be obtained by permeability saturation curve _w-S _w; Secondly, graphical method is adopted to obtain leading edge water saturation S _wf(see Fig. 2, namely on the relation curve of moisture content and water saturation, cross irreducible water saturation point and make curve near tangent, the water saturation corresponding to the intersection point of tangent line and curve is leading edge water saturation), and at f _w-S _wrelation curve obtains the moisture content f that leading edge water saturation is corresponding _w(S _wf) and irreducible water saturation S _wc, then according to formula try to achieve the derivate of water content ratio f ' that leading edge water saturation is corresponding _w(S _wf), given water breakthrough time T, according to formula try to achieve oilwell produced fluid amount Q ₂; Finally, the assumed value Q of oilwell produced fluid amount is judged ₁with calculated value Q ₂whether equal, as equal, just can obtain the Liquid output of oil well under this water breakthrough time, as unequal, again suppose that the Liquid output of oil well carries out calculating till equal.

In above formula, μ _o, μ _w, k _ro, k _rw, b, l, Δ ρ, α are respectively viscosity of crude, formation water viscosity, oleic permeability, water phase permeability, absolute permeability weighted average (being called for short permeability in literary composition), flooding unit width, core intersection weighted average, injector producer distance, degree of porosity weighted average, profit density contrast and stratigraphic dip.

Above-mentioned iterative method is adopted to try to achieve the Liquid output Q of oil well in each flooding unit respectively _1i(wherein i corresponds to producing well sequence number).

3. a note is adopted well group more and is determined water injection rate determination oilwell produced fluid amount

Try to achieve the Liquid output Q of each oil well _1iafterwards, according to the well water injection rate Q that oil field actual conditions are determined _t, judge oilwell produced fluid amount sum ∑ Q _1iwith well water injection rate Q _twhether equal, as equal, then each Liquid output Q now _1ibe the reasonable liquid measure of each oil well, as unequal, change water breakthrough time T returns step 2 and recalculates until ∑ Q _1iand Q _tequal.

4. the actual Liquid output of mining site oil well is adjusted to reasonable liquid measure and produces

According to the reasonable Liquid output of each oil well determined, adjust the working system (as stroke, jig frequency etc.) of each pumping unit of well at mining site, each oil well is produced according to the reasonable Liquid output determined.

Accompanying drawing explanation

Fig. 1 is that a note four of the present invention adopts the method that well group determines water injection rate determination oilwell produced fluid amount---note is adopted control area and is split a point schematic diagram;

Fig. 2 is that a note four of the present invention adopts the method that well group determines water injection rate determination oilwell produced fluid amount---graphical method solves leading edge water saturation.

Detailed description of the invention

For making the present invention become apparent, hereafter elaborate.

Step 1, note is adopted control area and to be split point and parameter equivalent process, and an actual note being adopted more well group equivalent process is that multiple one-dimensional linear displacement one note one adopts unit; Step 2, a given water breakthrough time, calculates the Liquid output of each flooding unit oil well; Step 3, according to the well water injection rate that oil field actual conditions are determined, judges that whether oilwell produced fluid amount sum is equal with well water injection rate, as equal, then Liquid output is now the reasonable liquid measure of each oil well, and as unequal, changing the water breakthrough time recalculates oilwell produced fluid amount till equal; Step 4, according to the reasonable Liquid output of each oil well determined, adjusts the working system of each pumping unit of well at mining site, the Liquid output of each oil well is produced according to the reasonable Liquid output determined.

Pungent oil field, east is typical Complex Fault Block Oil Reservoir, and three shaerbuer mountain forever are wherein medium to high permeable oil reservoir.Choosing the Five-point method pattern that one of them note four adopts is example, and elaborate, concrete implementation step is as follows:

1. note is adopted control area and to be split point and parameter equivalent process

For Five-point method pattern, an actual note is adopted well group division more and become four one-dimensional linear displacement one notes one to adopt unit, wherein I is water injection well, and P1, P2, P3 and P4 are producing well, corresponding flooding unit number consecutively.The formation parameter at known each injection-production well well point place, obtains the layer parameter fifty-fifty of each flooding unit, for flooding unit 1 according to the method (3) in parameter equivalent process:

${\stackrel{\‾}{h}}_1=(h_{o1}+h_w)/2=(5.0+7.0)/2=6.0m$

${\stackrel{\‾}{k}}_1=(k_{o1}{h}_{o1}+k_w{h}_w)/(h_{o1}+h_w)=(300\×5.0+470\×7.0)/(5.0+7.0)\×{10}^{-3}=399.2\×{10}^{-3}{\mathrm{\μm}}^2$

${\stackrel{\‾}{\mathrm{\φ}}}_1=({\mathrm{\φ}}_{o1}{h}_{o1}+{\mathrm{\φ}}_w{h}_w)/(h_{o1}+h_w)=(24\%\×5.0+24\%\×7.0)/(5.0+7.0)=24\%$

The layer parameter fifty-fifty of other 3 flooding units is tried to achieve in the same way, the results are shown in Table 1.

Table 1 basic parameter table

Note: above-mentioned stratigraphic dip is positive number, this represents that oil well is in the high flooding unit adopting type of low note; When oil well is in that high note is low adopts the flooding unit of type, stratigraphic dip is negative.

2. iterative method calculates the Liquid output determining oil well under the water breakthrough time

Suppose water breakthrough after 2 years, adopt iterative method to try to achieve the Liquid output of oil well: assuming that oilwell produced fluid amount is Q ₁, according to the design formulas of moisture content the change curve f of moisture content with water saturation can be obtained by the permeability saturation curve in this oil field _w-S _w; Graphical method is adopted to obtain leading edge water saturation S _wfand the derivate of water content ratio f ' of correspondence _w(S _wf), according to formula try to achieve oilwell produced fluid amount; Judge the assumed value Q of oilwell produced fluid amount ₁with calculated value Q ₂whether equal, as equal, just can obtain the Liquid output of oil well under given water breakthrough time T, as unequal, again suppose that the Liquid output of oil well carries out calculating till equal.For flooding unit 1, demonstration computational process, in table 2.

Table 2 iterative method calculates oilwell produced fluid amount

From the result of calculation of table 2, when the water breakthrough time is 2 years, the oilwell produced fluid amount of flooding unit 1 is 18.6827m ³/ d.

Repeat above-mentioned steps, calculate the oilwell produced fluid amount obtaining flooding unit 2,3 and 4 and be respectively 32.6793m ³/ d, 22.6102m ³/ d, 8.25771m ³/ d.

3. a note is adopted well group more and is determined water injection rate determination oilwell produced fluid amount

According to the well water injection rate Q that oil field actual conditions are determined _tfor 100m ³/ d, when the water breakthrough time is decided to be 2 years, the Liquid output sum of four mouthfuls of oil wells is not equal to Q _t; Change the water breakthrough time, the reasonable liquid measure adopting above-mentioned iterative method to try to achieve 4 mouthfuls of oil wells as water breakthrough time T=3.17 is followed successively by 23.3m ³/ d, 41.1m ³/ d, 27.7m ³/ d and 7.9m ³/ d, the Liquid output sum of four mouthfuls of oil wells equals Q _t, now four liquid measures are the reasonable liquid measure of four mouthfuls of wells.

4. mining site oil well is produced according to the reasonable Liquid output determined

According to the reasonable liquid measure of the four mouthfuls of oil wells determined, in the working system of mining site by each pumping unit of well of adjustment, each oil well is produced according to the reasonable Liquid output determined above.Produce after 3 months, well group moisture content drops to 89.7% from 96.3% before adjustment, and daily oil production adds 6.6m ³/ d, three months cumulative rises oil production 321m ³, according to oil price 100 dollars of/barrel of calculating, increase the output value 13.48 ten thousand yuan.

As can be seen from the Adjustment effect of an above well group, by means of only the adjustment just energy suggestions for improvement of liquid measure, improve oilfield economic benefit.An oil field has some well groups to form, if apply the method in oil field, greatly will improve the development effectiveness in oil field, improves oil field oil production, greatly increases the economic benefit in oil field.The method has great popularizing application prospect.

Claims (7)

1. a note adopts the method that well group determines water injection rate determination oilwell produced fluid amount more, comprises the following steps:

(1) note is adopted control area and to be split point and parameter equivalent process, and an actual note being adopted more well group equivalent process is that multiple one-dimensional linear displacement one note one adopts unit;

(2) a given water breakthrough time, the Liquid output of each flooding unit oil well is calculated;

(3) according to the well water injection rate that oil field actual conditions are determined, judge that whether oilwell produced fluid amount sum is equal with well water injection rate, as equal, then the reasonable liquid measure of oilwell produced fluid amount now and oil well, as unequal, changing the water breakthrough time recalculates oilwell produced fluid amount till equal;

It is characterized in that, in step (1), an actual note n being adopted well group division is that a n note one adopts unit, and the control area that each note one adopts unit gets the area surrounded between the angular bisector of adjacent two pairs of producing wells line separately and between water injection well; After each control area is determined, each note one is adopted unit and be reduced to the ribbon one-dimensional linear displacement model adopted along each note on line direction, the length of this one-dimensional linear displacement model is the distance between injection-production well, wide is the control area of corresponding flooding unit and the ratio of injector producer distance, thus it is equal with the control area of the one-dimensional linear displacement model after process to ensure that a note one before treatment adopts unit.

2. a note according to claim 1 adopts the method that well group determines water injection rate determination oilwell produced fluid amount more, it is characterized in that, in step (1), adopt angular bisectrix method to split the control area that a point note adopts each flooding unit of well group more, and an actual note to be adopted more well group equivalent process be that multiple one-dimensional linear displacement one note one adopts unit.

3. a note according to claim 1 and 2 adopts the method that well group determines water injection rate determination oilwell produced fluid amount more, it is characterized in that, calculates the equivalent parameters of each flooding unit according to following formula, i.e. core intersection weighted average degree of porosity weighted average with permeability weighted average

(1) distribution function h (x, y), the φ (x, y, z) of each parameter, k (x, y, z) in known formation:

$\stackrel{\‾}{h}=\frac{1}{A}\underset{A}{\∫\∫}h(x,y)dxdy$

$\stackrel{\‾}{\mathrm{\φ}}=\frac{1}{V}\underset{V}{\∫\∫\∫}\mathrm{\φ}(x,y,z)dxdydz$

$\stackrel{\‾}{k}=\frac{1}{V}\underset{V}{\∫\∫\∫}k(x,y,z)dxdydz$

(2) distribution function h (x, y), φ (x, y), the k (x, y) of each parameter on known injection-production well line:

$\stackrel{\‾}{h}=\frac{1}{L}\underset{L}{\∫}h(x,y)ds$

$\stackrel{\‾}{k}=\frac{1}{L}\underset{L}{\∫}k(x,y)ds$

(3) parameter value at known each injection-production well well point place:

$\stackrel{\‾}{h}=(h_o+h_w)/2$

$\stackrel{\‾}{\mathrm{\φ}}=({\mathrm{\φ}}_o{h}_o+{\mathrm{\φ}}_w{h}_w)/(h_o+h_w)$

$\stackrel{\‾}{k}=(k_o{h}_o+k_w{h}_w)/(h_o+h_w)$

Wherein, h _oand h _wbe respectively the core intersection of producing well, location, water filling well point layer; φ _oand φ _wbe respectively the degree of porosity of producing well, location, water filling well point layer; k _oand k _wbe respectively the permeability of producing well, location, water filling well point layer, A is the area of flooding unit, and V is the volume of flooding unit, and x, y, z is the position coordinates of any point, and L is injector producer distance.

4. a note according to claim 1 and 2 adopts the method that well group determines water injection rate determination oilwell produced fluid amount more, it is characterized in that, in step (2), first supposes that an oilwell produced fluid amount is Q ₁, adopt Q ₁value calculates moisture content and corresponding leading edge water saturation, then tries to achieve oilwell produced fluid amount Q according to leading edge water saturation and given water breakthrough time ₂; Finally, the assumed value Q of oilwell produced fluid amount is judged ₁with calculated value Q ₂whether equal, as equal, just can obtain the Liquid output of oil well under this water breakthrough time, as unequal, again suppose that the Liquid output of oil well carries out calculating till equal.

5. a note according to claim 4 adopts the method that well group determines water injection rate determination oilwell produced fluid amount more, wherein according to the design formulas of moisture content and phase percolation curve obtains the change curve f of moisture content with saturation ratio _w-S _w; Graphical method is adopted to obtain leading edge water saturation S _wf, at f _w-S _wrelation curve obtains the moisture content f that leading edge water saturation is corresponding _w(S _wf) and irreducible water saturation S _wc, and according to calculate corresponding derivate of water content ratio f ' _w(S _wf), a given water breakthrough time T, according to formula try to achieve oilwell produced fluid amount Q ₂, wherein, μ _o, μ _w, k _ro, k _rw, b, l, Δ ρ, α are respectively viscosity of crude, formation water viscosity, oleic permeability, water phase permeability, absolute permeability weighted average, flooding unit width, core intersection weighted average, injector producer distance, degree of porosity weighted average, profit density contrast and stratigraphic dip.

6. a note according to claim 5 adopts the method that well group determines water injection rate determination oilwell produced fluid amount more, and wherein graphical method is included in curve f _w-S _won, cross irreducible water saturation point and make curve near tangent, the water saturation corresponding to the intersection point of tangent line and curve is leading edge water saturation S _wf.

7. an oil production method, is characterized in that the reasonable liquid measure of each oil well that the method according to any one of claim 1-6 is determined, in the working system of mining site by each pumping unit of well of adjustment, each oil well is produced according to the reasonable Liquid output determined.