Be applicable to polynary transfer drive system and the transfer drive technology in water drive exploitation oil fieldTechnical field
The invention belongs to oil development technical field, relate in particular to the polynary transfer drive system and the transfer drive technology that are applicable to water drive exploitation oil field.
Background technology
The oil reservoir of the water drive of Gudao oilfield enforcement is at present mainly to turn water drive project and conventional water drive unit after poly-driving, high recovery rate, high recovery percent of reserves, high water-cut development stage are entered, in layer, interlayer, the large contradiction of plane three be more outstanding, water drive unit comprehensive is moisture has reached 93%, being equivalent to note 93 side's water can only 7 tons of crude oil of extraction, the invalid circulation of water filling seriously makes water drive unit at present in the poor efficiency development phase, along with the continuation of comprehensive water cut raises, oil-field development difficulty further strengthens, and economic benefit also worse and worse.How further to improve water drive unit recovery factor and development benefit and become the very urgent task of oil-field development.
But gather and drive rear unit because recovery percent of reserves further improves, remaining oil distribution is more scattered, Reservoir Heterogeneity further aggravates, conventional water-drive reservoir is due to physical property, economy and the poly-reasons such as technology of driving, increase the technical difficulty that improves recovery ratio, therefore be badly in need of exploring effective novel method, improve the development effectiveness of high water cut oil field.
Summary of the invention
The object of the invention is to, overcome the deficiencies in the prior art, a kind of polynary transfer drive system and transfer drive technology that is applicable to water drive exploitation oil field is provided.By the high-water-cut oil-producing well Water-Content Rise Reason-study to water drive exploitation oil field, rise for controlling well water, improve water drive exploitation effect, invent and in well the injecting process, noted nitrogen, foam, microballoon, oil-displacing agent multicomponent system and improve intake profile, improved the multicomponent system transfer drive technology of water drive swept volume.Solution water-drive field later stage section contradiction, channelling are given prominence to, the problems such as water-injection efficiency is low, rate of decline is fast, be applicable to the high water-cut well profile control application in water drive exploitation oil field, with conventional chemical flooding development scheme comparison, this technical superiority is the Application of composite to current transfer drive field novel process, not only realize the recovery ratio of the economic benefits and social benefits raising maturing field to improve displacement spread effect and displacement efficiency, and the environmental protection of material therefor, price advantage are obvious, implementing process is simple, greatly reduces technological investment cost.
For solving the problems of the technologies described above, technical scheme of the present invention is: be applicable to the polynary transfer drive system in water drive exploitation oil field, comprise nitrogen, foam, microballoon and oil-displacing agent.
Described microballoon is polymer microballoon, microballoon heatproof 60-95 DEG C, and salt tolerant 4000～10000mg/L, microballoon original dimension, all at nano level, is less than 200nm.Microballoon will have the good property noted, and can produce good plugging effect step by step, will have good shunting action to high low permeability cores, under indoor conditions, inject 0.3PV after height ooze streaming rate and will decline more than 85%.
Described whipping agent temperature resistant capability is greater than 70 DEG C, and the concentration in injection system is 0.3～0.5%, 0.5% whipping agent foam volume > 600ml, transformation period > 400s.
Described oil-displacing agent is modified carboxylate promoting agent, and temperature resistant capability is greater than 90 DEG C, and the mass concentration in injection system is 0.5～0.6%, and the interfacial tension of mass concentration 0.5% promoting agent and test site crude oil is less than 5 × 10-3mN/m.
Microballoon and nitrogen foam are profile control macropore plugging component, and wherein nitrogen foam system gas-liquid volume ratio should be controlled at 1:1 left and right.
The polynary transfer drive technology that is applicable to water drive exploitation oil field, comprises the following steps:
1) the profile control stage:
The first slug: microballoon profile control and nitrogen foam profile control, microballoon injection speed is normal waterflood injection rate 80%～90%, nitrogen injection rate is 600Nm3/ h, whipping agent injection rate is 7.5m3/ h, preparation whipping agent mass concentration is 0.5%, injects Injection Well oil pressure rising 2～3MPa by microballoon and nitrogen foam;
The second slug: polymer injection microballoon and polymer gel, wherein polymer microballoon implantation quality concentration is 0.1～0.5%, injection speed is 80%～90% of normal waterflood injection rate, injects by plugging and profile, and Injection Well oil pressure stops note and turns the displacement of reservoir oil stage while rising to lower than dry-pressing 0.5-1MPa;
Polymer gel is existing commercially available product, is polymers soln and linking agent and forms the plugging agent with some strength under certain condition.Polymers soln is that concentration is the polyacrylamide solution of 5000mg/L, and the mass ratio of linking agent and polymers soln is 0.4:100.Linking agent is existing commercially available product.
2) displacement of reservoir oil stage: the 3rd slug: microballoon profile control and oil-displacing agent, injection microballoon is polymer microballoon, injecting oil-displacing agent is the flooding system of mass concentration 0.6%, this flooding system is carboxylate salt and sulfonate, the mass ratio of carboxylate salt and sulfonate is 2:1, injection speed is normal waterflood injection rate, continues to inject 30～40d;
After having noted continuously with this step, the normal water filling of becoming a full member.
Condition of compatibility
(1) Reservoir Heterogeneity is strong, because foam, microballoon mainly result from the macropore of layer of sand, therefore selects to have the oil reservoir of higher permeability;
(2) oil and water well note is adopted correspondence better, the block of water dependent well comprehensive water cut >85%;
(3) after water drive, form macropore and alter stand in channel, corresponding well water rises fast, and oil well exists remaining oil enriched area in control area;
(4) in the low region of surplus oil to block up as main, exist local oil and water well water breakthrough passage area taking shutoff as main overall transfer drive technology;
(5) core intersection >=5 meter;
(6) down-hole casing is intact.
The invention has the beneficial effects as follows: the present invention utilizes high shutoff, the polymer microballoon oil displacement efficiency applied in any combination of deep transfer drive, modified carboxylate step by step of foam, reach the effect of 1+1+1 > 3, it is pioneering that technology belongs to, and level reaches international advanced.Section adjustment and the displacement of reservoir oil are combined the overall transfer drive improvement of strengthening water drive unit by this technology, on remaining oil distribution Research foundation, meticulous oil and water well section and the identification of macropore size and distribution, take in remaining oil enriched area to drive as main, to block up as main, exist local oil and water well water breakthrough passage area taking shutoff as main overall transfer drive technical thought in the low region of surplus oil.The successful Application of this technology can effectively improve the recovery ratio of follow-up water drive unit, becomes effective substituted technique that the maturing field degree of depth is taped the latent power, and has broad application prospects.The product system of this technology is high with cost performance under condition, and universality is good, is expected to become the material of maturing field stable yields measure, can mass-producing application.
Brief description of the drawings
Fig. 1 is GD1-4N13 well transfer drive construction oil pressure graphic representation;
Fig. 2 produces curve before and after GD1-4N13 well group profile control.
Embodiment
(1) first slug: microballoon profile control+nitrogen foam profile control
1, construction process:
Apply heavy dose of injection device and inject microballoon, application nitrogen car nitrogen injection foam system.
2, construction procedure:
(1) press construction process, connect pump and surface pipeline, each gate, switch are intact.
(2) pipeline pressure testing: pressure testing 15～20MPa does not sting, do not leak, debugging injection pump is working properly, and demarcates its discharge capacity and meet design requirements.
(3) injection test: turn on pump, injection test sewage 10m3, appraise and decide pumping rate, record injection test pressure.
(4) polymer injection microballoon: dosing method is (with 10m3pond is example): dosing adds 9m in pond3after sewage, add 30 kilograms of polymer microballoons, after stirring, add 5000mg/L polymer mother liquor 1m3, after stirring, start to inject.Inject displacement control at 7m3/ h.Note: can adjust polymer mother liquor add-on according to microballoon suspension situation.Polymer mother liquor used, is that polyacrylamide clear water is mixed with after 5000mg/L solution, then injects to on-the-spot desired concn with dilution of sewage, the polymers soln that conventionally clear water is mixed with to 5000mg/L is called polymer mother liquor.
(5) nitrogen foam: connection line pressure testing is qualified, nitrogen injection rate 600Nm3/ h, whipping agent injection rate 7.5m3/ h, preparation whipping agent mass concentration is 0.5%.
Concrete slug mode, discharge capacity, the proportioning injected is according to strata condition and on-the-spot injection pressure adjustment.
(2) second slugs: polymer microballoon+polymer gel
1, construction process:
Apply heavy dose of injection device and inject microballoon and jelly system.
2, construction procedure:
(1) according to construction process, connect pump and surface pipeline, each gate, switch are intact.
(2) pipeline pressure testing: pressure testing 15～20MPa does not sting, do not leak, debugging injection pump is working properly, and demarcates its discharge capacity and meet design requirements.
(3) injection test: turn on pump, injection test sewage 10m3, appraise and decide pumping rate, record injection test pressure.
(4) polymer injection microballoon: dosing method is (with 10m3pond is example): dosing adds 9m in pond3after sewage, add 25 kilograms of polymer microballoons, after stirring, add 5000mg/L polymer mother liquor 1m3, after stirring, start to inject.Injecting the control of discharge capacity, injection length determines according to well group situation.Note: can adjust mother liquor add-on according to microballoon suspension situation.
(5)polymer injection+linking agent system: dosing method is (with 10m3pond is example): dosing adds 4m in pond3after sewage, evenly add 5000mg/L polymer mother liquor 6m3, after stirring, add 20 kilograms of linking agents, after stirring, start to inject.Inject displacement control at 7m3/ h, injection length 48h.
(6) replace: replace sewage 20m3.
(7) Hou Ning: closing well Hou Ning turns displacement of reservoir oil slug after 3 days.
(3) the 3rd slugs: microballoon profile control+oil-displacing agent
1, construction process:
This slug injects by transfer drive flow process is set at water-injection plant, injection pump connects Injection Well pipeline, it in transfer drive tank, is the oil-displacing agent of design proportion, it in microballoon tank, is polymer microballoon, injection pump injection speed is adjusted according to design concentration, with water filling converge and after after static mixer mixes, be injected in water injection well.
2, construction procedure:
(1) according to construction process, connect pump and surface pipeline, each gate, switch are intact, and well is adjusted to injection allocation, normally injects, and records injection pressure.
(2) transfer drive flow process pipeline pressure testing: pressure testing is not stung, do not leaked, debugging micro pump injects working properly, and demarcates its discharge capacity and meet design requirements.
(3) microballoon, carboxylate salt, sulfonate injection rate injection length is determined according to well group situation
The effect of invention:
Since 2011, according to reservoir development and oil reservoir development signature analysis, at the GD1-4N13 well group of Ng4 unit, Gudao oilfield Zhong Yi district and cultivate western oil field and cultivate 622 and implemented nitrogen, foam, microballoon, the test of oil-displacing agent multicomponent system transfer drive Technology.By the end of in October, 2012, to implement altogether to inject 3 mouthfuls of well saliva wells, 14 mouthfuls of corresponding oil wells, are imitated 11 mouthfuls, and rate 79% takes effect.
(1) in profile control process, Injection Well oil pressure rises
After nitrogen foam+microballoon profile control, well head oil pressure is in rising trend.As the GD1-4N13 well group test site of Ng4 unit, Gudao oilfield Zhong Yi district, Injection Well GD1-4N13 well starts transfer drive construction from August, 2011, is divided into four slugs and injects, and within 1 month, completes injection, accumulative total injection profile liquid measure 3230 sides.Injection pressure rises to 9.1MPa by 7MPa, nitrogen mixed water injection pressure-stabilisation at 12MPa(as Fig. 1).Inject the oil pressure explanation nitrogen foam+microballoon profile control that raises and reached macropore plugging current and alter and stay passage, adjust intake profile, improve the object of displacement sweep efficiency.
(2) well group oil well oil increasing precipitation effect
The GD1-4N13 test site of Yi Zhong mono-Ng4 unit, district is example, and to produce dynamically after transfer drive, after nitrogen injection foam+microballoon transfer drive, GD1-4N13 well injects oil pressure and rises, and 1.5MPa has risen compared with before injecting; Corresponding well water declines, and average decline exceedes 1 percentage point, and well fluid level is also on a declining curve, and accumulative total increases 909 tons of oil, tentatively takes effect.See Fig. 2.