CN1414212A - Medium and low pormeability oil layer polymer oil displacing layer combination method - Google Patents
Medium and low pormeability oil layer polymer oil displacing layer combination method Download PDFInfo
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Abstract
The invented combining method of medium-and low-permeability oil layer and polymer oil displacing layer system possesses the following steps: (1) selecting a polymer displacement region block; (2) dividing deposition units; (3) analyzing the polymer displacement potential; (4) screening deposition units; and (5) combining the layer system. The invented method can effectively raise the oil layer recovering rate of a single oil layer with relatively low permeability and relatively thin effective thickness.
Description
Technical field
The invention belongs to oil recovery field, oil field, relate in particular to a kind of to each individual reservoir combination displacement of reservoir oil, particularly in the sedimentation unit using polymer technology of driving of low-permeability make up the method for the displacement of reservoir oil.
Background technology
For oil-bearing series is the multiple zone sandstone oil field of sand, mud stone alternating layers, can be subdivided into the individual reservoir that tens to more than 100 thin and thicks do not wait on the section.The permeability variation of reservoir is from 1 * 10
-3Um
2～1000 * 10
-3Um
2More than; Effective thickness changes from 0.2m to 10 more than many meters; Interlaced and the stack of the plane heterogeneity of oil bearing formation property and vertical heterogeneity significantly increases the oilfield water flooding development difficulty.The oil field enters after the late high water content period mining phase, thickness big (more than the general 2m-10m), permeability height (general effective permeability＞500 * 10 in the oil reservoir
-3μ m
2), large tracts of land distributes on the plane main force's thick oil pay or sandstone group adopt polymer displacement of reservoir oil tech to obtain good polymer flooding effect and remarkable economic efficiency.And for about effective thickness 0.2-5m, (the effective permeability 50 * 10 of low-permeability in the genus
-3μ m
2-500 * 10
-3μ m
2About) non-major oil reservoir because its main body sand body is to be the dendritic distribution of fillet band on the thick oil pay sand body plane, the polymer flooding difficulty is strengthened.
Goal of the invention
The object of the present invention is to provide a kind of low-permeability oil reservoir polymer displacement of reservoir oil series of strata combined method in the multiple zone sandstone oil field that is applicable to.By combined method provided by the invention, can be lower to permeability, the individual reservoir that effective thickness is thin carries out polymer flooding effectively and improves reservoir recovery.
To achieve these goals, the technical solution used in the present invention comprises:
1, the selection of polymer flooding block: the block reservoir condition is sand, mud stone alternating layers; Can be subdivided into the individual reservoir more than tens on the section, about effective thickness changes from 0.2 meter to 5 meters, its effective permeability changes from 50 * 10
-3Um
2-500 * 10
-3Um
2About, comprehensive water cut is at 85%-98%.
2, the division of sedimentation unit: utilize the fine geology research method vertically to segment sedimentation unit, segmentation sedimentary micro in plane marks off the base unit that series of strata make up.
3, poly-ly drive the analysis of block polymer flooding potentiality
(1) formation of oil in place and distribution:
A. reservoir geology reserves=area in the table * sand body bores encountering rate * brill and meets average thickness * unit reserve factor
B. step a is pressed the different-thickness grade, calculate the interior main body sand body of each sedimentation unit and the oil in place of non-main body sand body respectively.The oil in place of sedimentation unit=main body sand body oil in place+non-main body sand body oil in place
C. each sedimentation unit main body sand body oil in place that step b is calculated and non-main body sand body oil in place gather by the different-thickness grade just can obtain poly-distribution and formation of driving the block oil in place.
(2) the oil reservoir producing status is analyzed
A. utilize the suction situation of the isotope injection profile analysis different-thickness oil reservoir of well more than three times.Statistics different-thickness reservoir water flooding thickness and water out thickness percentage and not water out thickness and not water out thickness percentage.
B. utilize new well Water Flooding Layer interpretation data to analyze the water out behavior of different-thickness oil reservoir.Statistics different-thickness oil reservoir one-level, secondary, three grades of water out thickness and water out thickness percentage and not water out thickness and not water out thickness percentage.
C. utilize the washing situation of sealed coring analysis different-thickness oil reservoir.Statistics different-thickness oil reservoir is strong, in, weak washing thickness and washing thickness percentage and do not wash thickness and do not wash thickness percentage.
4) screening of sedimentation unit: need satisfy following condition
(1) the sedimentation unit effective thickness is greater than 1 meter;
(2) the brill encountering rate of the main sand body of sedimentation unit is not less than 20%;
(3) the main sand body oil in place of sedimentation unit proportion 〉=60%.
5) series of strata combination: the sedimentation unit that is fit to polymer flooding is made up by following principle
The maximum differential boundary of (1) one cover series of strata interlayer permeability is 5-7;
(2) one cover series of strata low-permeability oil reservoirs are that the shared thickness proportion of thin poor reservoir is less than 30%;
(3) one cover series of strata effective thickness boundary 8-14 rice, 10 meters the bests;
(4) one cover series of strata perforated interval length are 50 meters;
(5) the series of strata space layer should be greater than 3 meters.
More than provided the method for a kind of middle low-permeability oil reservoir polymer displacement of reservoir oil series of strata combination of the present invention.By the following examples, the invention will be further described.
Description of drawings
Fig. 1 concerns scatter diagram for individual reservoir effective thickness of the present invention and effective permeability;
Fig. 2 is each sedimentation unit reserves of the present invention and main body sand body brill encountering rate relation curve.
The specific embodiment
Embodiment 1:
The disconnected long-pending 25.79km in the east in Bei Yi district in the Sa
2, oil-bearing series is sand, mud stone alternating layers.Oil reservoir is vertically gone up and is made up of the individual reservoir more than tens, and about individual reservoir effective thickness 0.2-5m, effective permeability is 50 * 10
-3μ m
2-500 * 10
-3μ m
2About.Be subdivided into 58 sedimentation units vertically.Except that 8 sedimentation units of the I of Portugal group major oil reservoir that permeability height, thickness are big have been carried out the polymer displacement of reservoir oil low-permeability oil reservoir during 50 sedimentation units of all the other Sas+II of Portugal oil reservoir belong to, oil in place 12936 * 10
4T, recovery percent of reserves 40.18%, comprehensive water cut 88.6%.
Sedimentation unit is the base unit of series of strata combination.On the petroleum geology, adopt the control methods of cycle thickness and the electrofacies analysis method of " cycle contrast, grading control " that oil reservoir is vertically segmented sedimentation unit usually, segmentation sedimentary micro in plane marks off the base unit that series of strata make up.Single layer of sand that the one-time continuous with oil-containing sand body that sedimentation unit is separated with argillaceous rocks about being deposits.
Form by oil-containing sand body and non-oil-containing sand body on the sedimentation unit plane.The oil-containing sand body is that main body sand body, oil sheet are that non-main body sand body and off-balancesheet reservoir are formed by thick oil pay; Non-oil-containing sand body is that mud stone is the pinching district.Most of sedimentation unit thick oil pays are that main body sand body width is about 100-1200m, effective thickness is generally about 1-5m, be non-main body sand body, off-balancesheet reservoir, mud stone filling by thin layer sand between the main body sand body, wherein thin layer sand, off-balancesheet reservoir large tracts of land distribute, and mud stone pinching district is less.Thin layer sand be non-main body sand body effective thickness generally about 0.2-1.5m, effective permeability is 50 * 10
-3μ m
2-300 * 10
-3μ m
2About.The off-balancesheet reservoir does not have effect thickness, based on argillaceous siltstoue, and air permeability＜20 * 10
-3μ m
2-50 * 10
-3μ m
2Sedimentation unit average effective thickness is between 0.48m-2.12m.Have 30 sedimentation unit average effective thickness greater than 1m less than 2.0m, greater than the sedimentation unit oil reservoir of 1m vertically go up distribute more concentrated.The detailed division of each oil reservoir group sedimentation unit sees the following form 1.
The oil reservoir group sedimentation unit of disconnected Sector East, Bei Yi district piece is divided in table 1 Sa
| The oil reservoir group | The sandstone group | Sedimentation unit | The sedimentation unit number | ＞1m sedimentation unit number |
| One group of Sa | SI1-5 | ?SI1，SI2 1，2，SI3 1，2，SI4+5 1，2，3 | ?????8 | |
| Two groups of Sas | SII1-3、SII4-6、SII7-9、 SII10-12、SII13-16 | ?SII1，SII2 1，2，SII3，SII4，SII5+6 1， ?2，SII7，SII8 1，2，SII9，10，11， ?12，13，14，SII15+16 1，2， | ????18 | ?????16 |
| Three groups of Sas | SIII1-3、SIII4-7、 SIII8-10 | ?SIII1，SIII2，SIII3 1，2，SIII4， ?SIII5+6 1，2，SIII7，8，SIII9 1，2，SIII10 1， ?2， | 13 | ??????8 |
| One group of Portugal | PI1-4、PI5-7 | ?PI1，PI2 1，2，PI3，4，5，6，7 | ?????8 | ??????8 |
| Two groups of Portugals | PII1-3、PII4-6、PII7-9、 PII10 | ?PII1，2，3，4，5，6，7，8，9， ?PII10 1，2， | ????11 | ??????7 |
| Add up to | 15 | ????58 | ?????39 |
According to indoor polymer displacement of reservoir oil experimental result, adopt the polymer of 8,000,000 above molecular weight, the oil reservoir effective permeability can not be lower than 80 * 10
-3Um
2Adopt the polymer of 1,200 ten thousand molecular weight, the oil reservoir effective permeability is in 150-200 * 10
-3Um
2, inject and can not stop up.Fig. 1 is that individual reservoir effective thickness and effective permeability concern scatter diagram, and most 0.2-1m individual reservoir effective permeabilities are in 100-250 * 10
-3Um
2Between, therefore, adopting the polymer of 1,000 ten thousand molecular weight, the 0.2m individual reservoir injects and can not stop up substantially.
The reserves of oil reservoir calculated and all calculated the sandstone group in the past, in order to satisfy the needs of oil field late high water content period exploitation and tertiary oil recovery research, by Detailed Geologic Research Results-unit deposition facies tract figure reserves were calculated sedimentation unit.Off-balancesheet reservoir reservoir physical property is poor, sandstone thickness is little, saturating rate is low, the reserves proportion is low, and the poly-field test that drives shows that poly-the driving of this class reservoir do not employ, therefore, and the oil in place of reservoir in the computational chart here.Reservoir is not only to have had sandstone thickness but also had effective thickness and reservoir physical property oil reservoir preferably in the table, comprises thick oil pay and oil sheet, i.e. main body sand body and non-main body sand body.According to the research needs main body sand body in the sedimentation unit and non-main body sand body are divided into 〉=4m simultaneously,～2.1,2.0～1.6,1.5～1.0,0.9～0.5 ,≤0.4 etc. 3.9 6 level of thickness is calculated the oil in place of sedimentation units, the formation and the distribution of reflection oil in place that more can be careful.
The design formulas of reservoir geology reserves is in the table:
Reservoir geology reserves=area in the table * sand body bores encountering rate * brill and meets average thickness * unit reserve factor
The oil in place of sedimentation unit=main body sand body oil in place+non-main body sand body oil in place, unit 10
4T;
Area: refer to poly-block area, the unit K m of driving of single oil area
2
Oil area is the actual oil area of oil reservoir in each sedimentation unit table.Oil area=area * sand body bores encountering rate, unit K m
2
Oil area in the table=main body sand body oil area+non-main body sand body oil area;
Main body sand body oil area=block area * main body sand body bores encountering rate;
Non-main body sand body oil area=block area * non-main body sand body bores encountering rate;
Sand body bores encountering rate and is meant on unit deposition facies tract figure, and poly-interior all oil-water wells of block that drive bore the percentage that chance sand body well numbers account for total well number; Bore encountering rate as asking for 3.9～2.1m main body sand body, adding up the percentage that the well number that is drilled on 3.9～2.1m main body sand body accounts for total well number on the unit deposition facies tract figure.Unit deposition facies tract figure is a sedimentation time unit distribution map in the plane, it is Detailed Geologic Research Results, reflect main body sand body and non-main body sand body distribution situation and the position, well point on this sedimentation unit above it, all indicated sandstone thickness, effective thickness, the permeability value of this present position, well point sand body on each well point.
Bore and meet average thickness: refer to that on unit deposition facies tract figure oil-water well brill chance main body sand body or non-main body sand thickness sum are divided by boring the average of meeting this sand body well number, unit (m).Meet average thickness as the brill that will ask for 3.9～2.1m main body sand body, be drilled in the thickness of every mouthful of well on 3.9～2.1m main body sand body adding up on the unit deposition facies tract figure, again divided by the well number that is drilled on 3.9～2.1m main body sand body.
Unit reserve factor: be the oil in place of every square kilometre of oil area, unit thickness oil reservoir, unit 10
4T/Km
2.m; The main body sand body is taked different unit reserve factors with non-main body sand body.
Big for area, the poly-block that drives that the well number is many, main body sand body in each sedimentation unit and non-main body sand body can be divided into some level of thickness according to the research needs, well point parameter sandstone thickness, effective thickness, permeability input computer are set up database, finish the formation and the distribution work of oil in place by computer.
Result of calculation shows:
1. main body sand body reserves mainly are distributed in greater than 1m, in the oil reservoir less than 4m, account for similar sand
97.1% of body reserves.Non-main body sand body reserves mainly are distributed in＜oil reservoir of 1.5m in.Non-
Main body sand body＞1m reservoir geology reserves account for non-main body sand body reserves ratio 37.57% (table 2).
2. 72.52% of the Sa+II of Portugal reservoir geology reserves be distributed in the oil of effective thickness greater than 1.0m
In the layer, only account for 8.9% less than 0.5m reservoir geology reserves.
Table 2 anatomical area is pressed thickness statistic of classification oil in place table
| The effective thickness classification | The main body sand body | Non-main body sand body | Oil in place (10 4t) | Occupied area piece oil in place (%) | |||||
| Oil in place (10 4t) | Account for similar sand body (%) | Oil in place (10 4t) | Account for similar sand body (%) | ||||||
| ????＞4.0m | ??538.91 | ??7.1 | ??97.1 | ??15.50 | ??0.29 | 37.57 | ??554.4 | ?4.29 | ?72.52 |
| ??3.9～2.1m | ??4342.59 | ?57.18 | ??323.81 | ??6.06 | ??4666.39 | ?36.07 | |||
| ??1.6～2.0m | ??1215.61 | ?16.01 | ??331.28 | ??6.20 | ??1546.89 | ?11.96 | |||
| ??1.0～1.5m | ??1276.76 | ?16.81 | ??1336.33 | ??25.02 | ??2613.09 | ?20.20 | |||
| ??0.5～0.9m | ??205.23 | ?2.7 | ??2197.62 | ??41.14 | ??2402.85 | ?18.57 | |||
| ????＜0.5m | ??14.88 | ?0.20 | ??1137.16 | ??21.29 | ??1152.04 | ?8.9 | |||
| Add up to | ??7593.97 | ?100 | ??5341.68 | ??100 | ??12935.704 | ?100 | |||
The purpose of oil reservoir producing status analysis is to analyze the producing status of late high water content period oil in place.Comprehensive analysis method is adopted in the analysis of oil reservoir producing status, by driving in the block to poly-, isotope injection profile data, new well Water Flooding Layer interpretation data, three kinds of test data analysis-by-synthesis of sealed coring data oil reservoir producing status and poly-ly drive potentiality are oil field analytical methods commonly used.
Above-mentioned three kinds of data are consistent to the reflection of oil reservoir producing status, remaining oil one is to be present in the top of effective thickness greater than the 1.0m oil reservoir, this class remaining oil accounts for the Sa+II of Portugal reservoir geology reserves more than 1/5, is to adopt technique of polymer flooding to improve the main research direction of recovery ratio; The 2nd, be present in effective thickness＜0.5m oil reservoir and off-balancesheet reservoir behind the superencipher, it is bad that this two classes oil reservoir has 20%～30% thickness to employ.Effective thickness＞1.0m oil reservoir is employed relatively good, but serious heterogeneity in the layer, there have a half thickness to employ in the water drive condition lower floor to be bad, is fit to polymer flooding; It is little that effective thickness＜0.5m oil reservoir and off-balancesheet strata are driven potentiality.
By being analyzed us, the formation of reserves and producing status know that the thick oil pay of＞1m is the main object that polymer flooding is taped the latent power.The Bei Yi district eastern Sa+II of Portugal oil reservoir 50 sedimentation units from top to bottom of breaking, it is very big to bore the encountering rate difference with regard to the main body sand body, bores the encountering rate excursion at 0.69-54.21%.Each sedimentation unit reserves of disconnected east and main body sand body brill encountering rate relation curve (Fig. 2) from the Bei Yi district, when main body sand body＞20%, main body sand body reserves account for unit reserves ratio and reach more than 60%.
For more sedimentation unit can be selected in, reduce the reserves loss, main body sand body and non-main body sand body are carried out the combination of 6 kinds of schemes, study the relation that various combination sand bodies bore encountering rate and reserves, combined result sees Table 3.As seen from the table:
Scheme 1: consider with the main body sand body to be main sand body, when to bore encountering rate＞20%, main sand body accounts for unit reserves ratio＞70% and is boundary, and the unit that satisfies this condition only has 11; Main sand body is selected sand body.
Scheme 2: consider with the main body sand body to be main sand body, when to bore encountering rate＞20%, main sand body accounts for unit reserves ratio＞60% and is boundary, and the unit that then satisfies this condition only has 15, its reserves only occupied area piece reserves 46.76%, the sedimentation unit number of loss is more;
Scheme 3: consider with＞1m main body sand body and＞the non-main body sand body of 1m is main sand body, when to bore encountering rate＞20%, main sand body accounts for unit reserves ratio＞70% and is boundary, the unit that satisfies this condition only has 21;
Scheme 4: consider with＞1m main body sand body and＞the non-main body sand body of 1m is main sand body, when to bore encountering rate＞20%, main sand body accounts for unit reserves ratio＞60% and is boundary, the unit that then satisfies this condition has 25;
Scheme 5: consider with the main body sand body and＞the non-main body sand body of 1m is main sand body, when to bore encountering rate＞20%, main sand body accounts for unit reserves ratio＞70% and is boundary, satisfies 23 of the unit of this condition;
Scheme 6: consider with the main body sand body and＞the non-main body sand body of 1m is main sand body, when to bore encountering rate＞20%, main sand body accounts for unit reserves ratio＞60% and is boundary, satisfies 27 of the unit of this condition; Selected sand body accounts for cell-average reserves ratio and has reached 80.34%.Its reserves occupied area piece reserves rise to 72.52%, and the sedimentation unit number of loss is less, and have controlled most of oil in place.
27 sedimentation units that scheme 6 is selected in have only the selected sand body reserves of 4 unit to account for unit reserves ratio between 60%-70%, and the selected sand body reserves in all the other 23 unit account for unit reserves ratio＞70% (table 4).12 selected sand bodies in unit bore encountering rate and bore encountering rate greater than 25% (table 5) greater than the selected sand body in 30%, 7 unit, and 27 sedimentation unit average effective thickness are all greater than 1m.
Therefore, determine selected sedimentation unit average effective thickness greater than 1m, main sand body bores under the encountering rate and is limited to 20%, and main sand body accounts for unit reserves ratio 〉=60%.
Table 3 sedimentation unit sand body assembled scheme table
| The scheme numbering | The unit number | Oil in place (10 4t) | Occupied area piece reserves (%) | Cell-average reserves (10 4t) | Selected sand body accounts for cell-average reserves (%) | Sand body on average bores encountering rate (%) | Selected sand body accounts for unit reserves ratio limits | Sand body bores the encountering rate boundary | The sand body combination | |
| The main body sand body | Non-main body sand body | |||||||||
| ????1 | ??11 | ?4494 | ?34.73 | ?408.55 | ????76.80 | ??31.42 | ????＞＝70 | ??＞＝20 | The main body sand body | |
| ????2 | ??15 | ?6050 | ?46.76 | ?389.00 | ????73.12 | ??29.86 | ????＞＝60 | ??＞＝20 | ||
| ????3 | ??21 | ?7522 | ?58.14 | ?358.19 | ????81.88 | ??30.14 | ????＞＝70 | ??＞＝20 | ＞1m main body sand body | The non-main body sand body of＞1m |
| ????4 | ??25 | ?8889 | ?68.70 | ?341.75 | ????79.22 | ??29.29 | ????＞＝60 | ??＞＝20 | ||
| ????5 | ??23 | ?8158 | ?63.05 | ?354.70 | ????82.88 | ??32.44 | ????＞＝70 | ??＞＝20 | The main body sand body | The non-main body sand body of＞1m |
| ????6 | ??27 | ?9383 | ?72.52 | ?306.25 | ????80.34 | ??31.23 | ????＞＝60 | ??＞＝20 | ||
Table 4 sedimentation unit sand body assembled scheme table
| Selected sand body reserves account for unit reserves ratio (%) | Scheme 1 | | Scheme 3 | Scheme 4 | Scheme 5 | Scheme 6 |
| The unit number | The unit number | The unit number | The unit number | The unit number | The unit number | |
| ????＞70 | ????11 | ????11 | ????21 | ????21 | ????23 | ????23 |
| ????60-70 | ?????4 | ?????4 | ?????4 | |||
| Add up to | ????11 | ????15 | ????21 | ????25 | ????23 | ????27 |
Table 5 sedimentation unit sand body assembled scheme table
| Bore the encountering rate scope | Scheme 1 | Scheme 2 | Scheme 3 | Scheme 4 | Scheme 5 | Scheme 6 | ||||||
| The unit number | Ratio (%) | The unit number | Ratio (%) | The unit number | Ratio (%) | The unit number | Ratio (%) | The unit number | Ratio (%) | The unit number | Ratio (%) | |
| ???＞40 | ??1 | ??9.01 | ???1 | ??6.67 | ???3 | ??14.3 | ???3 | ??12.0 | ???4 | ??17.4 | ???4 | ??14.8 |
| ??30-40 | ??4 | ??36.4 | ???5 | ??33.3 | ???4 | ??19.5 | ???4 | ??16.0 | ???8 | ??33.3 | ???8 | ??29.6 |
| ??25-29 | ??3 | ??27.3 | ???3 | ??20.0 | ???7 | ??33.3 | ???9 | ??36.0 | ???5 | ??21.7 | ???7 | ??25.9 |
| ??20-24 | ??3 | ??27.3 | ???6 | ??40.0 | ???7 | ??33.3 | ???9 | ??36.0 | ???6 | ??26.1 | ???8 | ??29.6 |
| Add up to | ?11 | ???100 | ??15 | ???100 | ??21 | ???100 | ??25 | ???100 | ??23 | ???100 | ??27 | ???100 |
The interlayer permeability grade is meant when there being under the more stable interlayer condition that distributes the ratio of two individual reservoir mean permeabilities in the middle of two individual reservoirs.
1. set up 5 basic geology models, each geological model is divided into 5 uniform thickness substratums, all belongs to the positive rhythm oil reservoir, and the VK value is 0.65.The substratum permeability of each basic geology model sees Table 6.
Table 6 basic geology model
| Pattern number | ?????K ?(10 -3um 2) | ????K1 ?(10 -3um 2) | ????K2 ?(10 -3um 2) | ????K3 ?(10 -3um 2) | ????K4 ?(10 -3um 2) | ????K5 ?(10 -3um 2) |
| ????1 | ????200 | ????29 | ????67 | ????117 | ????205 | ????582 |
| ????2 | ????400 | ????59 | ????134 | ????233 | ????409 | ????1165 |
| ????3 | ????600 | ????88 | ????201 | ????350 | ????614 | ????1747 |
| ????4 | ????800 | ????117 | ????268 | ????466 | ????819 | ????2330 |
| ????5 | ????1000 | ????146 | ????335 | ????583 | ????1023 | ????2912 |
By synthetic 5 the double-deck geological models of basic geology model group, levels is not communicated with mutually then, and double-deck geological model sees Table 7.
The double-deck geological model of table 7
| Pattern number | ??????6 | ?????7 | ?????8 | ?????9 | ?????10 |
| Upper strata mean permeability (10 -3um 2) | ????1000 | ????800 | ????600 | ????400 | ????200 |
| Lower floor's mean permeability (10 -3um 2) | ????1000 | ????1000 | ????1000 | ????1000 | ????1000 |
| Interlayer permeability ratio | ????1.00 | ????1.25 | ????1.67 | ????2.50 | ????5.00 |
2. adopt the five-spot areal well pattern, injector producer distance 250m; Design polymer volume 380mg/L.PV, polymer solution concentration 1000mg/L, injection rate 0.19PV/a; To moisture 90%, polymer flooding ended by moisture 98% o'clock recovery process then from geological model initial time water drive.
2. the numerical simulation calculation result shows, accounts at the low-permeability core intersection under 29% the condition of gross thickness, and the interlayer permeability grade increases at 5.0 o'clock from 1.25, and recovery ratio reduces by 2.97 percentage points; When the interlayer permeability grade is 5, low-permeability core intersection ratio less than 29% o'clock to polymer flooding influential effect less (table 8,9).
Table 8 interlayer permeability grade is to the influence of polymer flooding effect (low-permeability core intersection account for gross thickness 29%)
| The interlayer permeability grade | Moisture (%) | Inject hole multiple (PV) | Recovery ratio (%OOIP) | Recovery ratio drop-out value (%OOIP) |
| ????1.25 | ????98.0 | ????2.14 | ????53.98 | ?????0.00 |
| ????1.67 | ????98.0 | ????2.33 | ????52.72 | ?????0.26 |
| ????2.50 | ????98.0 | ????2.62 | ????52.96 | ?????1.02 |
| ????5.00 | ????98.0 | ????3.07 | ????51.01 | ?????2.97 |
Table 9 low-permeability core intersection ratio is to the influence of polymer flooding effect
| Low-permeability core intersection ratio (%) | Moisture (%) | Inject hole multiple (PV) | Recovery ratio (%OOIP) | Recovery ratio drop-out value (%OOIP) |
| ????17 | ????98.0 | ????3.37 | ?????52.77 | ????0.00 |
| ????29 | ????98.0 | ????3.07 | ?????51.01 | ????1.76 |
| ????38 | ????98.0 | ????2.85 | ?????49.69 | ????3.08 |
| ????44 | ????98.0 | ????2.70 | ?????48.81 | ????3.96 |
| ????50 | ????98.0 | ????2.55 | ?????47.93 | ????4.84 |
The low-permeability oil reservoir was poly-during disconnected west, Bei Yi district was ongoing drives field test and also shows, be under 5 the condition in the interlayer permeability grade, the ratio that low-permeability, thin poor reservoir thickness account for gross thickness is greater than 30% injection well, the poly-injection pressure height that drives, well stimulation is frequent, and producing well feed flow situation is poor.
During the combination of water drive straticulate exploration, the interlayer permeability grade is decided to be 3-5.Because polymer can reduce the permeability of high permeability or high Water Flooding Layer significantly, adjust intake profile, dwindle interlayer contradiction, so during the combination of polymer flooding straticulate exploration, the interlayer permeability grade can be bigger than the interlayer permeability grade of water drive straticulate exploration.But because polymer molecular weight and reservoir permeability are that certain matching relationship is arranged, when cover series of strata are injected a kind of polymer flooding molecular weight, can not be too big once the interlayer permeability grade of overlapping series of strata.If the interlayer permeability grade is bigger, the permeability of low-permeability oil reservoir is too low, will cause polymer plugging or notes not to advance the low-permeability oil reservoir, and impact polymer drives effect.
In sum, a cover series of strata interlayer permeability grade maximum figure is comparatively reasonable at 5-7, and the low-permeability core intersection accounts for the ratio of gross thickness should be less than 30%.
The big major oil reservoir industrialization polymer flooding one cover series of strata effective thickness of regional permeability height to the north of in the Sa, thickness is between 13.0-14.0m, it accounts for more than 85% of gross thickness greater than 2m sedimentation unit oil reservoir, series of strata perforated interval length (table 10) about 20-30m.For major oil reservoir, because approaching the little number of plies of difference layer, increases in middle low-permeability oil reservoir, so the interlayer thickness of interlayer also increases thereupon.If a cover series of strata effective thickness also is decided to be 13.0-14.0m, then because thin poor number layer by layer increases, and the shared full well thickness proportion of thin difference layer thickness increases greater than 30% injection-production well, the well segment length increases, the interlayer contradiction increase; If a cover series of strata effective thickness is decided to be 6.0-7.0m, because series of strata thickness is little, then the less injection-production well ratio of effective pay thickiness is big, and poor efficiency well ratio is big, influences polymer flooding effect; If a cover series of strata effective thickness is decided to be about 10.0m, then perforated interval length is about 50m.Because series of strata thickness is moderate, the less injection-production well ratio of effective pay thickiness is little, and the shared full well thickness proportion of thin difference layer thickness is few greater than 30% well, and interlayer contradiction is less.Table 11 listed in the disconnected west, Bei Yi district 13 mouthfuls of injection well＜1m of low-permeability oil reservoir polymer flooding and＞1m effective thickness proportion and individual well effective thickness.This cover series of strata well average effective thickness 8.8m, 2 mouthfuls of well effective pay thickiness＜5m only, the 4 mouthfuls of thin difference of wells layer thicknesses account for full well thickness proportion more than 30%, and wherein 3 mouthfuls of well polymer inject difficulty take place.
Therefore, a cover polymer flooding straticulate exploration oil reservoir average effective lower thickness limit is defined as 8m, and the upper limit is defined as 14m, and with 10m the best, this moment, perforated interval length was about 50m.
Each sedimentation unit effective thickness proportion table of western major oil reservoir breaks in table 10 Bei Yi district
The II7-10 of I5-7+ Portugal of low-permeability oil reservoir Portugal injects well in the disconnected west, table 11 Bei Yi district
| Sedimentation unit | Effective thickness (m) | Element thickness ratio (%) | |
| The I1 of Portugal 1 | ????0.8 | ?????????6.0 | |
| The I2 of Portugal 1 | ????4.0 | ????30.3 | ? ? ???88.7 |
| The I2 of Portugal 2 | ????2.2 | ????16.7 | |
| The I2 of Portugal 3 | ????5.5 | ????41.7 | |
| The I4 of Portugal | ????0.7 | ?????????5.3 | |
| Add up to | ????13.2 | ????????100.0 | |
＜1m and 〉=1m effective thickness proportion statistical form
| ????????????????????????????＜1m | ???????????????????≥1m | Full well | ||||||||||
| Pound sign | The number of plies (individual) | Sandstone (m) | Effectively (m) | Effective permeability (μ m 2) | Effective ratio (%) | The number of plies (individual) | Sandstone (m) | Effectively (m) | Effective ratio (%) | The number of plies (individual) | Sandstone (m) | Effectively (m) |
| ??5-P26 | ??0 | ?0 | ?0 | ????0.18 | ?????0.0 | ????3 | ??15.3 | ???8.7 | ????100.0 | ???3 | ??15.3 | ???8.7 |
| ??J6-P22 | ??6 | ?9 | ?1.9 | ????0.18 | ????26.8 | ????1 | ??5.4 | ???5.2 | ????73.2 | ???7 | ??16.8 | ???7.1 |
| ??J6-P23 | ??5 | ?7.6 | ?1.5 | ?????0.2 | ????34.9 | ????1 | ??6 | ???3.7 | ????86.0 | ???7 | ??12.7 | ???4.3 |
| ??B1-6-23 | ??7 | ?9.7 | ?2.3 | ????0.05 | ????28.0 | ????3 | ??7.4 | ???5.9 | ????72.0 | ???10 | ??17.1 | ???8.2 |
| ???6-G25 | ??8 | ?5.8 | ?1.1 | ????10.9 | ????3 | ??12.2 | ?????9 | ????89.1 | ???11 | ??18 | ???10.1 | |
| ???7-P22 | ??6 | ?8.4 | ?1.5 | ????0.05 | ????17.6 | ????4 | ??10.8 | ?????7 | ????82.4 | ???10 | ??19.2 | ???8.5 |
| ???7-P23 | ??3 | ?13.6 | ?1 | ?????6.4 | ????3 | ??16 | ??14.7 | ????93.6 | ???6 | ??29.6 | ???15.7 | |
| ??Z1-P26 | ??3 | ?4.8 | ?0.9 | ????0.08 | ?????9.7 | ????5 | ??11.9 | ???8.4 | ????90.3 | ???8 | ??16.7 | ???9.3 |
| ??Z1-P28 | ??8 | ?11.6 | ?2 | ????0.06 | ????25.3 | ????3 | ??6.4 | ???5.9 | ????74.7 | ???11 | ??18 | ???7.9 |
| ??CJ2-P5 | ??5 | ?10.3 | ?1.9 | ????0.07 | ????15.0 | ????2 | ??11.6 | ??10.8 | ????85.0 | ???7 | ??21.9 | ???12.7 |
| ??C2-P104 | ?12 | ?13.3 | ?4.1 | ????0.24 | ????57.7 | ????1 | ??3.2 | ?????3 | ????42.3 | ???13 | ??16.5 | ???7.1 |
| ??CJ2-P4 | ??9 | ?7.8 | ?2.5 | ????0.25 | ????67.6 | ????1 | ??4 | ???1.2 | ????32.4 | ???10 | ??11.8 | ???3.7 |
| ??B1-6-27 | ??7 | ?8.9 | ?2.8 | ????0.04 | ????34.6 | ????4 | ??9.3 | ???5.3 | ????65.4 | ???11 | ??18.2 | ???8.1 |
| Add up to | ??79 | ?111 | ?23.5 | ???34 | ??119.5 | ??88.8 | ???114 | ??231.8 | ???111.4 | |||
| On average | ??6.1 | ?1.4 | ?0.29 | ????0.09 | ?2.61 | ??3.51 | ??2.61 | ???8.76 | ??17.8 | ???8.8 | ||
Compartment thickness is greater than 3m between the series of strata, and requires the sealing quality good, prevents to annotate oil reservoir generation channelling between the different series of strata under the poly-back injection pressure rising 3-5.0MPa situation.
According to low-permeability oil reservoir choosing layer and series of strata combination principle in above-mentioned, the poly-straticulate exploration (table 12) of driving of one-tenth 4 covers capable of being combined.
Low-permeability oil reservoir series of strata combination table in the disconnected east, table 12 Bei Yi district
Embodiment 2:
| Series of strata | The sandstone group | The unit | Element thickness (m) | Bore encountering rate % | Unit reserves (10 4t) | Main sand body ratio % |
| The first cover series of strata | ???SII1-3 | ????SII2 1 | ????1.699 | ????38.24 | ?????467 | ?????86 |
| ????SII2 2 | ????1.754 | ????44.88 | ?????540 | ????87.81 | ||
| ????SII3 | ????1.141 | ????26.28 | ?????284 | ????75.1 | ||
| ???SII14-6 | ????SII4 | ????1.126 | ????27.9 | ?????355 | ????65.71 | |
| ???SII7-9 | ????SII7 | ????1.492 | ????38.64 | ?????378 | ????86.96 | |
| ????SII8 1 | ????2.122 | ????60.34 | ?????708 | ????94.2 | ||
| ????SII8 2 | ????1.502 | ????43.89 | ?????451 | ????86.33 | ||
| ????SII9 | ????1.195 | ????24.78 | ?????248 | ????77.63 | ||
| Subtotal | ????12.031 | ????3427 | ||||
| The second cover series of strata | ???SII10-12 | ????SII10 | ????1.586 | ????32.3 | ?????335 | ????87.93 |
| ????SII11 | ????1.779 | ????38.43 | ?????370 | ????93.09 | ||
| ????SII12 | ????1.576 | ????32.2 | ?????344 | ????86.39 | ||
| ???SII13-16 | ????SII13 | ????1.487 | ????28.72 | ?????309 | ????83.92 | |
| ????SII14 | ????1.278 | ????29.19 | ?????370 | ????73.22 | ||
| Subtotal | ????7.706 | ????1728 | ||||
| The 3rd cover series of strata | ???SIII1-3 | ????SIII2 | ????1.25 | ????20.94 | ?????245 | ????78.75 |
| ????SIII3 1 | ????1.072 | ????22.45 | ?????275 | ????69.93 | ||
| ???SIII4-7 | ???SIII5+6 1 | ????1.195 | ????31.27 | ?????391 | ????70.23 | |
| ???SIII5+6 2 | ????1.419 | ????32.37 | ?????381 | ????81.87 | ||
| ??SIII8-10 | ????SIII8 | ????1.848 | ????30.15 | ?????331 | ????88.24 | |
| ????SIII9 1 | ????1.352 | ????20.47 | ?????188 | ????84.1 | ||
| ????SIII9 2 | ????1.685 | ????27.74 | ?????261 | ????91.67 | ||
| Subtotal | ????9.821 | ?????2072 | ||||
| The quadruplet series of strata | ???PII1-3 | ????PII2 | ????1.193 | ????26.72 | ?????346 | ????62.13 |
| ????PII3 | ????1.719 | ????46.88 | ?????581 | ????75.47 | ||
| ???PII4-6 | ????PII5 | ????1.13 | ????24.63 | ?????244 | ????74.54 | |
| ????PII6 | ????1.311 | ????23.11 | ?????197 | ????84.82 | ||
| ???PII7-9 | ????PII7 | ????1.207 | ????22.82 | ?????225 | ????79.81 | |
| ????PII8 | ????1.338 | ????27.91 | ?????310 | ????78.24 | ||
| ????PII9 | ????1.017 | ????20 | ?????249 | ????65.18 | ||
| Subtotal | ????8.915 | ?????2152 | ||||
| Cell-average | ????1.424 | ????31.23 | ?????347.52 | ????80.34 |
Sa north regional Bei San district western thick-layer trial zone gross area 0.319Km
2, voids volume 72.82 * 10
4m
3, original oil in place 41.09 * 10
4T.The trial zone adopts five-spot areal well pattern, 9 mouthfuls of producing wells, 4 mouthfuls of injection wells, injector producer distance 200m.Trial zone SII10-16 oil reservoir is on average penetrated out sandstone thickness 9.84m, average effective thickness 8.86m, mean permeability 0.301 μ m
2, coefficient of permeability variation 0.725.The reservoir parameter of trial zone meets the determined middle low-permeability oil reservoir series of strata combination condition of the inventive method, sees the following form 13,14.
Table 13 oil reservoir base data table
| Sedimentation unit | On average penetrate to have and imitate thickness (m) | Average effective permeability (μ m 2) |
| ???SII10-11 | ?????1.6 | ?????0.2762 |
| ???SII12 | ?????1.6 | ?????0.3188 |
| ???SII13+14 1 | ?????2.37 | ?????0.3745 |
| ???SII13+14 2 | ?????1.23 | ?????0.2965 |
| ???SII15+16 | ?????2.0 | ?????0.2912 |
| ???SII10-16 | ?????1.76 | ?????0.3154 |
Cell data tables such as table 14 trial zone deposition
| Project | Series of strata combination requirement | Actual oil reservoir data |
| The main sand body of sedimentation unit bores encountering rate % | ?????＞20％ | ????＞30％ |
| The main sand body reserves of sedimentation unit account for sedimentation unit reserves ratio (%) | ?????＞60％ | ????＞70％ |
| Cell-average thickness (m) | ?????＞1m | ????1.76m |
| Permeability grade between the unit | ?????5-7 | ????4-5 |
| The one cover total effective thickness of series of strata (m) | ?????10m | ????8.8m |
| Thin difference layer thickness ratio (%) | ?????＜30％ | ????＜30％ |
| Series of strata space layer (m) | ?????＞3m | ????＞3m |
| The trial zone is moisture 83-96% just | ????85-98％ | ????93.3％ |
The polymer displacement of reservoir oil field test has carried out the series of strata combination by low-permeability oil reservoir series of strata combined method in of the present invention to the SII10-16 oil reservoir.Following injection parameter injection of polymer solution is adopted in test:
1, year injection rate 0.19PV; 2, polymer volume 570mg/L.PV; 3, polymer implantation concentration 1000mg/L.When whole district's moisture content reached 98%, centerwell 333 well polymer floodings improved recovery ratio 10.15% than water drive, and the ton polymer increases oily 109t.This polymer flooding oil test has obtained good polymer flooding effect by low-permeability oil reservoir series of strata combined method in of the present invention.
Claims (3)
1, a kind of middle low-permeability oil reservoir polymer displacement of reservoir oil series of strata combined method, its step is as follows:
1) selection of polymer flooding block: the block reservoir condition is sand, mud stone alternating layers; Can be subdivided into the individual reservoir more than tens on the section, about effective thickness changes from 0.2 meter to 5 meters, its effective permeability changes from 50 * 10
-3Um
2-500 * 10
-3Um
2About, comprehensive water cut is at 85%-98%.
2) division of sedimentation unit: utilize the fine geology research method vertically to segment sedimentation unit, segmentation sedimentary micro in plane marks off the base unit that series of strata make up.
3) poly-ly drive the analysis of block polymer flooding potentiality
(1) formation of oil in place and distribution:
A. reservoir geology reserves=area in the table * sand body bores encountering rate * brill and meets average thickness * unit reserve factor
B. step a is pressed the different-thickness grade, calculate the interior main body sand body of each sedimentation unit and the oil in place of non-main body sand body respectively.The oil in place of sedimentation unit=main body sand body oil in place+non-main body sand body oil in place
C. each sedimentation unit main body sand body oil in place that step b is calculated and non-main body sand body oil in place gather by the different-thickness grade just can obtain poly-distribution and formation of driving the block oil in place.
(2) the oil reservoir producing status is analyzed
A. utilize the suction situation of the isotope injection profile analysis different-thickness oil reservoir of well more than three times.Statistics different-thickness reservoir water flooding thickness and water out thickness percentage and not water out thickness and not water out thickness percentage.
B. utilize new well Water Flooding Layer interpretation data to analyze the water out behavior of different-thickness oil reservoir.Statistics different-thickness oil reservoir one-level, secondary, three grades of water out thickness and water out thickness percentage and not water out thickness and not water out thickness percentage.
C. utilize the washing situation of sealed coring analysis different-thickness oil reservoir.Statistics different-thickness oil reservoir is strong, in, weak washing thickness and washing thickness percentage and do not wash thickness and do not wash thickness percentage.
4) screening of sedimentation unit: need satisfy following condition
(1) the sedimentation unit effective thickness is greater than 1 meter;
(2) the brill encountering rate of the main sand body of sedimentation unit is not less than 20%;
(3) the main sand body oil in place of sedimentation unit proportion 〉=60%.
5) series of strata combination: the sedimentation unit that is fit to polymer flooding is made up by following principle
(1) one cover series of strata interlayer permeability grade boundary is 5-7;
(2) one cover series of strata low-permeability oil reservoirs are that the shared thickness proportion of thin poor reservoir is less than 30%;
(3) one cover series of strata effective thickness boundary 8-14 rice, the best is 10 meters;
(4) one cover series of strata perforated interval length are 50 meters;
(5) the series of strata space layer is answered 〉=3 meters.
2, low-permeability oil reservoir polymer displacement of reservoir oil series of strata combined method in as claimed in claim 1 is characterized in that, reservoir is not only to have had sandstone thickness but also had effective thickness and reservoir physical property oil reservoir preferably in the described table.
3, middle low-permeability oil reservoir polymer displacement of reservoir oil series of strata combined method as claimed in claim 1 is characterized in that, described area is meant the poly-block area that drives of single oil area.
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| CN 01136654 CN1414212A (en) | 2001-10-25 | 2001-10-25 | Medium and low pormeability oil layer polymer oil displacing layer combination method |
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|---|---|---|---|
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Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100429528C (en) * | 2005-08-10 | 2008-10-29 | 大庆油田有限责任公司 | Method of deposition phase control for casting sandstone oil reservoir attribute |
| CN103993862A (en) * | 2014-02-12 | 2014-08-20 | 中国石油天然气股份有限公司 | Stratification developing method for complex fault block thin oil reservoir |
| CN104110242A (en) * | 2013-08-30 | 2014-10-22 | 中国石油化工股份有限公司 | Method for increasing extraction rate of later exploitation stage of heterogeneous reservoir |
| CN109281642A (en) * | 2018-10-18 | 2019-01-29 | 中国石油化工股份有限公司 | A method of improving postpolymer flood stratified reservoir development effectiveness |
-
2001
- 2001-10-25 CN CN 01136654 patent/CN1414212A/en active Pending
Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN100429528C (en) * | 2005-08-10 | 2008-10-29 | 大庆油田有限责任公司 | Method of deposition phase control for casting sandstone oil reservoir attribute |
| CN104110242A (en) * | 2013-08-30 | 2014-10-22 | 中国石油化工股份有限公司 | Method for increasing extraction rate of later exploitation stage of heterogeneous reservoir |
| CN104110242B (en) * | 2013-08-30 | 2016-09-14 | 中国石油化工股份有限公司 | A kind of method improving heterogeneous reservoir development late stage recovery ratio |
| CN103993862A (en) * | 2014-02-12 | 2014-08-20 | 中国石油天然气股份有限公司 | Stratification developing method for complex fault block thin oil reservoir |
| CN103993862B (en) * | 2014-02-12 | 2016-02-10 | 中国石油天然气股份有限公司 | Complex fault block ligh-oil reservoir hierarchical-development method |
| CN109281642A (en) * | 2018-10-18 | 2019-01-29 | 中国石油化工股份有限公司 | A method of improving postpolymer flood stratified reservoir development effectiveness |
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