Oil-water well alternately coupling note adopts the method improving and close craven fault block reservoirs recovery ratioTechnical field
The present invention relates to Complex Fault Block Oil Reservoir development scheme and improve recovery ratio field, particularly relating to a kind of oil-water well and replace the method being coupled and noting and adopt and improve and close craven fault block reservoirs recovery ratio.
Background technology
The geology characteristic of Complex Fault Block Oil Reservoir is that area is little, and plane geometry of the reservoir is various, and close, longitudinal upper small layer is many, and non-average is strong.The note that its reservoir characteristic causes in exploitation adopts contradiction, i.e. the well water filling then rapid water logging of oil well, and it is not enough that well stops noting then oil well liquid-supplying, and when stablizing water filling, inject water and flow along main stream line, impact scope is little, tomography angle, disconnected sideband remaining oil are difficult to employ, and recovery percent of reserves is low.Current research shows, the reasons such as well spacing is little, longitudinal physical difference cause oil-water well main stream line position, main layer barometric gradient larger, and disconnected sideband, the poor layer of physical property due to barometric gradient less, development degree is poor, but does not also have both at home and abroad effective means to solve this note to adopt contradiction, increase substantially Complex Fault Block Oil Reservoir water drive further and involve degree.Our difficult point of facing for complex fault block geology characteristic and exploitation for this reason, invented a kind of oil-water well alternately coupling note adopt the method improving Complex Fault Block Oil Reservoir recovery ratio, solve above-mentioned technical problem.
Summary of the invention
The object of this invention is to provide a kind of oil-water well and replace the method that coupling note adopts the closed craven fault block reservoirs recovery ratio of raising, change the injection-production method that tradition note adopts connection, interlock is adopted by stratum reconstruction and note, becoming stable note adopts as oil-water well in plane and the alternately coupling note longitudinally between upper many cover series of strata are adopted, set up the displacement pressure reduction of disconnected sideband and tomography angle district remaining oil, improve center main streamline region oil displacement efficiency, reach the object improving pole Complex Fault Block Oil Reservoir recovery ratio.
Object of the present invention realizes by following technical measures: oil-water well alternately coupling note adopts the method improving and close craven fault block reservoirs recovery ratio, this oil-water well alternately coupling note is adopted and is improved the method closing craven fault block reservoirs recovery ratio and comprise: step 1, selectedly implements alternately coupling and notes the Complex Fault Block Oil Reservoir of adopting; Step 2, analyzes the Developing status of oil reservoir, determines that can implement alternately coupling notes the oil-water well adopted; And step 3, determine that implementing alternately coupling notes the technical policy of adopting.
Object of the present invention also realizes by following technical measures:
In step 1, according to the geologic feature of oil reservoir, oil property and Developing status, screening can implement oil-water well alternately coupling note the Complex Fault Block Oil Reservoir of adopting.
In step 1, selected oil reservoir meets the following conditions: fault block is closed, and area is little, and well number is few, and plane sand body connectedness is good, oil viscosity <35mPas, stratigraphic dip >5 °.
In step 2, for individual layer oil reservoir, an employing note is not adopted, only adopt the note do not noted mode alternately of adopting is coupled.
In step 2, for stratified reservoir, at multiple substratum reservoir properties, oil water relation, water out behavior, grow these data every interlayer and carry out on the basis of classification of assessment, combination is optimized to the substratum of the series of strata of two couplings, switch under suitable interval lower going-into-well, period 1 first series of strata only adopt do not note, another series of strata only note and do not adopt, next cycle first series of strata only note do not adopt, another series of strata only adopt and do not note, realize responding curve of well on ground, the note of two cover series of strata adopts alternately coupling.
In step 3, stress level, the note Discharge rate situation current according to oil reservoir, determine that implementing alternately coupling notes pressure maintenance level, pressure recover mode and the oil-water well working system of adopting, to reach the object expanding water drive and involve, improve recovery ratio.
In step 3, stress level returns to more than original formation pressure to make oil well maintenance enough energy.
In step 3, pressure recover mode is recover by level or once recovers.
In step 3, the initial stage adopts higher well injection rate, to be restored near original formation pressure time, the preferred Reasonable Injection speed of adopting of oil-water well enters note and adopts CGCM.
Oil-water well in the present invention alternately coupling note adopts the method improving and close craven fault block reservoirs recovery ratio, interlock is adopted by stratum reconstruction and note, becoming stable note adopts as oil-water well in plane and the alternately coupling note longitudinally between upper many cover series of strata are adopted, set up the displacement pressure reduction of disconnected sideband and tomography angle residual oil area, expand the impact scope injecting water, thus improve pole Complex Fault Block Oil Reservoir recovery ratio.The method loses by oil-water well in plane the alternately injection-production method that series of strata in face, longitudinal direction lose face, solve the difficult problems such as the little waterflood caused of Complex Fault Block Oil Reservoir oil-water well injector producer distance is fast, water drive impact scope is little, there is ground oil-water well responding curve of well, feature that actual operation is strong.The method effectively can solve Complex Fault Block Oil Reservoir note and adopt contradiction, expands the impact scope injecting water, improves the development degree at the disconnected non-master streamline position such as sideband, tomography angle, thus reaches the object improving Complex Fault Block Oil Reservoir recovery ratio.This invention for improve development effect in complex fault-block reservoirs, improve oil recovery provide a kind of new method, there is wide popularizing application prospect, significant economic and social benefits can be obtained.
Accompanying drawing explanation
Fig. 1 is the flow chart that oil-water well of the present invention replaces that coupling note adopts the specific embodiment improving the method closing craven fault block reservoirs recovery ratio;
Fig. 2 is that the longitudinal stratified reservoir note during the present invention specifically implements adopts first cycle schematic diagram of coupled modes;
Fig. 3 is that the longitudinal stratified reservoir note during the present invention specifically implements adopts second cycle schematic diagram of coupled modes.
Detailed description of the invention
For making above and other object of the present invention, feature and advantage can become apparent, cited below particularly go out preferred embodiment, and coordinate institute's accompanying drawings, be described in detail below.
As shown in Figure 1, Fig. 1 is the flow chart that oil-water well of the present invention replaces that coupling note improves a specific embodiment of oil recovery method.
In step 101, the selected closed craven fault block reservoirs implemented alternately coupling note and adopt.According to the geologic feature of oil reservoir, oil property and Developing status, screening can implement oil-water well alternately coupling note the Complex Fault Block Oil Reservoir of adopting.This oil reservoir meets the following conditions: fault block is closed, and area is little, and well number is few, and plane sand body connectedness is good, oil viscosity <35mPas, stratigraphic dip >5 °.Flow process enters into step 102.
In step 102, the Developing status of oil reservoir, injection-production well condition, longitudinal substratum to be grown and the data such as producing status is analyzed, determine that can implement alternately coupling notes the oil-water well adopted.For individual layer oil reservoir, an employing note is not adopted, only adopt the note do not noted mode alternately of adopting is coupled, for stratified reservoir, at multiple substratum reservoir properties, oil water relation, water out behavior, carry out on the basis of classification of assessment every data such as interlayer growths, combination is optimized to the substratum of the series of strata of two couplings, switch under suitable interval lower going-into-well, period 1 first series of strata only adopt do not note, another series of strata only note and do not adopt, next cycle first series of strata only note do not adopt, another series of strata only adopt and do not note, realize responding curve of well on ground, the note of two cover series of strata adopts alternately coupling.What Fig. 2 and Fig. 3 showed is the coupling of stratified reservoir two being overlapped to series of strata, and display is coupled as two cover series of strata, and the left side is water injection well, the right side is producing well, and Fig. 2 is upper half period, and upper strata is only noted and do not adopted, and lower floor only adopts and do not note.Fig. 3 is that the longitudinal stratified reservoir note during the present invention specifically implements adopts second cycle schematic diagram of coupled modes, upper strata only adopt do not note, lower floor only notes and do not adopt, realize responding curve of well on ground, the notes of two cover series of strata adopt alternately coupling.Flow process enters into step 103.
In step 103, determine that implementing alternately coupling notes the technical policy of adopting.The stress level, note Discharge rate situation etc. current according to oil reservoir, determine that implementing alternately coupling notes the technical policies such as pressure maintenance level, pressure recover mode and the oil-water well working system of adopting, to reach the object expanding water drive and involve, improve recovery ratio.Stress level returns to more than original formation pressure and keeps enough energy to make oil well; Pressure recover mode can recover by level or once recover; Initial stage adopts higher well injection rate, to be restored near original formation pressure time, the preferred Reasonable Injection speed of adopting of oil-water well enters note and adopts CGCM.Flow process terminates.
In application embodiments of the invention 1, oil field 1 is a closed Complex Fault Block Oil Reservoir, reservoir buried depth 2710m, oil area 0.13km2, ground viscosity of crude 15-34.7mPas, oil in place 10 × 104t, stratigraphic dip 16.2 °.Open oil well 1 mouthful before test, day produce oil 0.4t/d, comprehensive water cut 96.7%, recovery percent of reserves 9.4%, oil reservoir whole development effect is poor.
This block oil well is because High water cut returning other series of strata, and augmented injection implemented by well, and raises injection allocation, day note 60 side, intensification flooding, only note is not adopted, and injection-production ratio reaches 1.5 and stops note, small casing under high-order bit workover, heavily penetrate rear lower pump to produce, moisturely drop to 52%, day oil rise to 7.5t/d.
(1) according to this reservoir geologic character, oil property and Developing status, contrast screening criteria.This oil reservoir meets screening conditions: fault block is closed, and area is little, and well number is few, and plane sand body connectedness is good, oil viscosity <35mPas, stratigraphic dip >5 °.
(2) develop As-Is analysis to this block, this block low position well L17-103 can continue water filling and possess to raise injection allocation space, can stop this well water filling after stratum energy abundance, and high-order bit recovers oil well L36-10 by overhaul and recovers the oil at this layer.
(3) well L17-103 raises injection allocation, day note 60m3/ d, arrives after near original formation pressure until pressure recover, and heavily penetrate lower pump after high-order bit oil well L36-10 well overhaul and produce, well stops note simultaneously, enter into oil-water well alternately coupling note adopt pattern.
When whole experimental stage does not bore new well, individual well day oil be increased to 7.5t by 0.5t, water ratio in oil well drops to 52% by 96.7%, improve recovery percent of reserves 1.33%, achieve good implementation result.