Summary of the invention
It is an object of the invention to overcome above-mentioned problems of the prior art, relatively grow for crackFine and close oil reservoir, waterflooding extraction water breakthrough risk is big；In the case of improving well yield, improve reservesDevelopment degree.Giving full play to the draining effect of volume fracturing seam net, horizontal well region is all by pressure break simultaneouslySeam net covers, and proposes a kind of Oil in Super-low Permeability compact oil reservoir volume fracturing horizontal well quasi-natural energy exploitation staggeredWell-arranging procedure.
To this end, the invention provides a kind of Oil in Super-low Permeability compact oil reservoir quasi-natural energy of volume fracturing horizontal wellThe staggered well-arranging procedure of exploitation, comprises the steps:
1) layer of sand isogram, oil reservoir isogram, porosity isopleth map, permeability are first drawnIsogram, shows that the region of high level carries out horizontal well patterns deployment in this four classes figure, carries out reservoirEvaluation of classification, determines that the main force contributes interval；
2) optimization of horizontal section length
Application method for numerical simulation, sets up reservoir uniform soft soil base, the list under simulation varying level segment lengthWell capacity determines the horizontal well length when internal rate of return (IRR) is the highest.
3) optimization of well spacing
(1) preferred according to fracturing technology
Guaranteeing to be formed between horizontal well effectively design level well well spacing in the case of seam net, according to fine and close oilVolume fracturing seam net monitoring result determines the well spacing of horizontal well.
(2) preferred according to Production development
Volume fracturing horizontal productivity is by reservoir properties, fracturing reform scale, well pattern form, horizontal segmentThe combined influence of length etc., utilization regards horizontal well under day this parameter comparison difference well spacing of production fluid and produces dynamicState situation,
Wherein, liquid measure/discharge capacity × 1000, ground are entered depending on day production fluid=day production fluid/pressure break hop count/single hop
In combination with the fracture length of volume fracturing transformation, determine the well spacing of rational horizontal well；
4) optimization of pressure-break certain distance
According to the different production times regard day production fluid with the Production development of certain distance, the initial stage of going into operation, half a year andReasonable certain distance is determined when reaching maximum depending on day production fluid after 1 year.
5) array pitch is determined
From plane, the pressure-break spacing of upper and lower two mouthfuls of water horizontal well joining place horizontal wells transformation is defined asArray pitch, is considered as array pitch by the certain distance of pressure-break, determines rational array pitch.
Above-mentioned steps 1) specifically include following steps:
1. combine sedimentary microfacies map, diagenesis phasor and porosity, permeability figure, select porosity and connectivityBe worth the highest region, regional deployment horizontal well patterns that residue non-producing reserves are largest；
2. the selective perforation interval operation yield oil layer section higher than 2t/d, contributes interval for the main force, asInterval met by the brill of horizontal well.
Above-mentioned steps 2) in, the design length of described horizontal well is 800m～1000m.
Above-mentioned steps 3) in, the well spacing of described horizontal well is 550-650m.
Above-mentioned steps 3) in, the well spacing of described horizontal well is specially 600m.
Above-mentioned steps 4) in, determined by rationally certain distance in the range from 80-100m.
Above-mentioned steps 4) in, determined by rationally certain distance be 90m.
Above-mentioned steps 5) in, described rational array pitch is in the range from 80-100m.
Above-mentioned steps 5) in, described rational array pitch is specifically identified as 90m.
Between above-mentioned horizontal well, well spacing is 2 times of artificial fracture half length.
Beneficial effects of the present invention: fine and close oil reservoir is grown in crack relatively, and horizontal well is staggered, and hands overWrong cloth seam, performs to the limit by the natural energy draining effect of horizontal well volume fracturing seam net.EvadeThe water breakthrough risk of waterflooding extraction, volume fracturing stagnant liquid serves the initial stage and supplements the effect of energy.OneSame oil reservoir can be realized on individual well site and bore 4 mouthfuls of water horizontal wells, carry out factory operation.
Below with reference to accompanying drawing, the present invention is described in further details.
Detailed description of the invention
Below in conjunction with Fig. 1 and Fig. 2, a kind of Oil in Super-low Permeability compact oil reservoir volume fracturing water that the present invention is providedThe staggered well-arranging procedure of horizontal well quasi-natural energy exploitation is described in detail.
Wherein method and the basic principle of well net optimization design is: one is integrated application reservoir engineering, numberThe methods such as value simulation and mining site statistics, consider technical specification and economic indicator simultaneously；Two is to playThe ability of extensive volume fracturing, increases substantially well yield.Applicable elements: crack is grown relativelyFine and close oil reservoir.
The present invention has taken into full account that fine and close oil reservoir is grown in crack relatively, by carrying out integrated geological interpretationWith ultra-low penetration compact oil reservoir non linear fluid flow through porous medium study mechanism, analysis and summary horizontal well over the years difference well patternOn the basis of implementation result, innovation proposes the Oil in Super-low Permeability compact oil reservoir quasi-natural energy of volume fracturing horizontal wellThe staggered well-arranging procedure of amount exploitation, the present invention uses:
(1) horizontal well is staggered, and between horizontal well, well spacing is 2 times of artificial fracture half length, realThe all standing of seam net, the man-made fracture of volume fracturing transformation and unlatching is realized between existing two horizontal wellsIntrinsic fracture is interweaved, staggered cloth seam, and seam net all covers horizontal well cloth wellblock, at utmost sends outWave the draining effect of seam net.
(2) natural energy exploitation, relies on volume fracturing to enter ground liquid measure big, still suffers from after the row of returning in stratumA large amount of stagnant liquids, supplement stratum energy to a certain extent, play the effect of Advance Water Injection.
(3) be conducive to carrying out cluster drilling, based on cluster drilling, form central water supply, alternatelyPressure break, the horizontal well factory operation pattern that concentration fracturing liquid reclaims, significantly investment reduction cost,Increase economic efficiency.
(4) combine horizontal well volume fracturing quasi-natural energy development process to be divided into initial stage stable yields, passSubtract the Development Practice of the three phases that comparatively fast and stably successively decreases, it is determined that different phase oil recovery technique policy.
Wherein the design length of horizontal well is 800m～1000m, and the well spacing of horizontal well is 600m；RationallyCertain distance is about 90m.
As shown in drawings, Fig. 1 shows quasi-natural energy horizontal well patterns and element schematic diagram；
Fig. 2 shows cluster drilling schematic diagram；Wherein: 1 horizontal section length, 2 well spacings, 3 splitSeam density (crack certain distance), 4 array pitch, 5 positions, well site.
1) layer of sand isogram, oil reservoir isogram, porosity isopleth map, permeability are first drawnIsogram, shows that the region of high level carries out horizontal well patterns deployment in this four classes figure, carries out reservoirEvaluation of classification, determines that the main force contributes interval；
1. combine sedimentary microfacies map, diagenesis phasor and porosity, permeability figure, select porosity and connectivityBe worth the highest region, regional deployment horizontal well patterns that residue non-producing reserves are largest；
2. according to the Production development of directional well, the perforated zone operation yield oil layer section higher than 2t/d, forMain force's contribution interval, interval met by the brill as horizontal well.
2) optimization of horizontal section length 1
Application method for numerical simulation, sets up reservoir uniform soft soil base, the list under simulation varying level segment lengthWell capacity, according to analog result it can be seen that under quasi-natural energy exploit condition, horizontal section lengthThe longest, single well productivity is the highest, but horizontal section length is longer means that scale of investment is relatively big, integrated economicsBenefit evaluation result is it can be seen that when horizontal section length is 800m～1000m, and the internal rate of return (IRR) isHigh.In view of all restrictions of site contour landforms, in conjunction with numerical simulation and the conclusion of economic evaluation,The reasonable length determining quasi-natural energy development level section is 800～1000m.
3) optimization of well spacing 2
(1) preferred according to fracturing technology
Horizontal Well away from design must assure that to be formed between horizontal well and effectively stitch net.And densification oil body overstocksFracture network monitoring result shows: after volume fracturing, fracture half-length reaches more than 300m, and fracture width is near100m.In consideration of it, determine that long horizontal sections five-spot pattern well spacing is 600m.
(2) preferred according to Production development
Volume fracturing horizontal productivity is by reservoir properties, fracturing reform scale, well pattern form, horizontal segmentThe combined influence of length etc., utilization regards horizontal well under day this parameter comparison difference well spacing of production fluid and produces dynamicState situation.
Liquid measure/discharge capacity × 1000, ground are entered depending on day production fluid=day production fluid/pressure break hop count/single hop
By above formula it can be seen that eliminate volume fracturing transformation scale and horizontal segment length depending on day production fluidThe degree impact on production capacity, is conducive to contrast reservoir fluid supply capacity, the most corresponding well pattern parameter.Tie simultaneouslyClose the fracture length of volume fracturing transformation, determine that rational well spacing is 600m.
4) optimization of pressure-break certain distance
According to when pacifying different production under the fine and close oil volume pressure break quasi-natural energy development scheme of 83 wellblock length 7Between regard day production fluid with the Production development of certain distance, after go into operation initial stage, half a year and 1 year regarding day production fluid allReach maximum when certain distance is 90m, development effectiveness is best, it is thus determined that long 7 fine and close oil are accurate naturalThe energy exploitation reasonable certain distance of volume fracturing horizontal well is about 90m.
5) array pitch 4
From plane, the pressure-break spacing of upper and lower two mouthfuls of water horizontal well joining place horizontal wells transformation is defined asArray pitch 4.Volume fracturing horizontal well quasi-natural energy well pattern form seam net all covers horizontal well cloth wellblock,So array pitch 4 is equivalent to the certain distance of pressure-break, rational array pitch is about 90m.
Cluster drilling (Fig. 2) according to current drilling technology requirement, before Horizontal Well Targets away from > 260m, skewAway from > 200m, a well site can realize same oil reservoir and bore 4 mouthfuls of water horizontal wells, carry out factory and be turned intoIndustry.
The practical example of industry
Utilize a kind of ultra-low penetration compact oil reservoir horizontal well well-arranging procedure acquired by the present invention at E ErduoJi Yuan oil field, this basin length 7 oil reservoir achieves preferable development effectiveness.
Pacify 83 wellblock length 72Belong to northeast sedimentary system, major developmental delta front sub-facies, pacify 83 wellsDistrict's main layer length 722Sandbody distribution direction is by sedimentary facies control, in east northeast-Nan Xi to spread, sandbody widthAbout 14.0km, average sand thickness reaches 17.0m, and sand layer thickness is the most thinning to both sides along main abrasive band,Monolayer sand thickness relatively thin (generally 3～8m), multi depositional stages river course is stacked forms thick sand body.The main forceLayer is long by 722Average oil layer thickness 10m, average pore 8.9%, mean permeability 0.17mD.For low hole,Hypotonic lithological pool.
The well-arranging procedure utilizing the present invention is pacified 83 wellblock length 7 reservoir intrinsic fractures and is relatively grown in northern Shensi, throwsProducing 115 mouthfuls of quasi-natural energy development level wells, initial stage development effectiveness is preferable, individual well initial stage, oil-producing day10.1t, initial stage rate of oil production 1.4%, average production 13 months, well all adds up oil-producing 1873t, opensSend out effect preferable.
6 mouthfuls of average shaft buildings of well of factory operation well group 20.1 days, 22.3 days formation testing cycles, average waterFlat segment length 917m, reservoir-encountered rate 91.1%, transform 9 sections 19 bunches, average individual well adding ceramic 554m3,Sand ratio 12.4%, discharge capacity 6.0m3/min；Initial stage average individual well day oil-producing 12.2t, aqueous 35.6%；Average individual well day oil-producing 6.7t, aqueous 42.5%.
In present embodiment, the part of not narration in detail belongs to the known conventional means of the industry, hereDescribe the most one by one.Exemplified as above is only the illustration to the present invention, is not intended that the present invention'sThe restriction of protection domain, every protection model belonging to the present invention with the same or analogous design of the present inventionWithin enclosing.