A kind of system enclosure method for oil shale underground in situ exploitationTechnical field
It is more particularly to a kind of for oil shale underground in situ exploitation the present invention relates to a kind of ground in-situ system enclosure methodSystem enclosure method.
Background technology
Oil shale in-situ production technique is a kind of new oil shale mining type after oil shale retorting, and it is by boringThe mode such as hole and hydraulic fracturing, forms heating passage, to oil shale after thermal source entrance heating passage in subterranean oil shale rock stratumHeating destructive distillation is carried out, the air-fuel mixture product of generation is derived to earth's surface through recovery well and carries out separating treatment.The oil shale that compares is doneTechnology is evaporated, oil shale in-situ production technique has ground installation few, and floor space is small, small grade is polluted in production process significantly excellentPoint.
Oil shale in-situ exploitation needs form one in underground mainly includes that oil shale heats passage and oil shale layer crackClosing exploitation space.The exploitation space of such a closing, is conducive to controlling the scope of oil shale in-situ exploitation, it is to avoid formerThe adverse effects such as oil gas leakage are produced in the recovery process of position to outside stratum.In the exploitation space of such a high temperature, especiallyIt is noted that the influence that underground water and the exploitation of temperature diffusion couple are produced.On the one hand, if having water in exploitation space or not exploitedThe characteristics of heat insulation work in space, specific heat big due to water, a big chunk heat will be only absorbed by the water, and exploitation is unable to reach in spaceIdeal temperature, influences oil shale recovery efficiency.On the other hand, if having water in exploitation space, even if generating oil gas, oil gasA large amount of vapor can be carried and return to earth's surface, while the work of oil supply gas-water separation brings difficulty, be greatly reduced returning for oil gasProduce effects rate.If exploitation space is connected with underground aquaporin, the pollutant produced in recovery process can enter underground reservoir,Polluted underground water.Therefore, it is particularly important for the production zone of oil shale provides closing space.
The ground in-situ production practice (ICP) of Shell Co. Ltd proposes a kind of underground freezing wall technology, with heated well andIt is certain and be interconnected to form the freezing well of closed system that producing well certain distance bores many mouthfuls of spacing, to injecting uniform temperature in wellFreezing liquid in system interior circulation, the underground water around well is formed freezing wall with surrounding rocks.But underground freezes answering for wallDuring, there is long construction period, power consumption is high, and the shortcomings of polluting is produced to underground water.
Patent CN102278116B provides a kind of cold districts and makes underground freezing wall device and make freezing wallMethod.The method is sent the low-temperature receiver obtained from winter outdoor temperature by the use of the low-temperature glycol aqueous solution as circulatory mediatorEnter in the hole beaten in advance, freeze geologic body, and then form freezing wall.The method construction can only in the winter time and winter temperature is coldArea is carried out, and limits larger, without the condition being widely popularized.
The content of the invention
The method presence that closing space is provided the invention aims to solve the existing production zone for oil shale is appliedThe work cycle is long, high energy consumption, pollution environment, the problem being subject to seasonal restrictions, and the one kind for providing is applied to different buried depth difference thicknessOil shale underground in situ exploitation system enclosure method.
Closed system involved in the present invention is by the heat-insulated confining bed of top board, floor spacer confining bed and horizon mining regionClosing curtain composition.
The present invention is comprised the following steps：
The first, floor spacer confining bed is set at oil shale layer base plate, oil shale in-situ production zone is covered, is opened with levelExploiting field domain closing curtain is connected to become entirety；
It is to bore a series of fracture grouting of quincuncial arrangements on ground for the fracture grouting method of floor spacer confining bedHole, the grouting serous fluid in adjacent fracture grouting hole mutually goes here and there footpath, and hole depth reaches oil shale layer base plate.
Injected hole passes through oil shale layer base plate, using the grouting mode of protrusive, slip casting, slurries is carried out in oil shale base plateUnder the action of pulling stress that pressure manages direction more than oil shale in-situ perpendicular to layer, oil shale layer of riving, the splitting route of slurriesIn crisscross veiny network, slurries mutually go here and there footpath in each injected hole, form floor spacer confining bed.
The 2nd, the heat-insulated confining bed of top board is set at oil shale top plate, oil shale in-situ production zone is covered, top board is setHeat-insulated confining bed makes slurries in each injected hole mutually go here and there footpath using the method for fracture grouting.
It is to bore a series of fracture grouting of quincuncial arrangements on ground for the fracture grouting method of the heat-insulated confining bed of top boardHole, the grouting serous fluid in adjacent fracture grouting hole mutually goes here and there footpath, and hole depth reaches oil shale layer top board.
Injected hole passes through oil shale layer top board, using the grouting mode of protrusive, slip casting, slurries is carried out in oil shale top boardUnder the action of pulling stress that pressure manages direction more than oil shale in-situ perpendicular to layer, oil shale layer of riving, the splitting route of slurriesIn crisscross veiny network, slurries mutually go here and there footpath in each injected hole, form the heat-insulated confining bed of top board；
Closing mud i.e. fracture grouting slurries are poured into fracture grouting hole, one-way valve tube is inserted to oil shale layer top board,Grouting serous fluid to be cleaved is set in one-way valve tube, is inserted into slip casting core pipe in one-way valve tube, carries out slip casting；Work as slurry pressureDuring more than oil shale in-situ vertical stratification direction tension, slurries are rived in oil shale layer and entrance crack, form top board heat-insulatedConfining bed.
3rd, closing curtain in horizon mining region is continuous and closed, using the method for osmotic grouting, through the oily page of exploitationRock stratum base plate, reaches the basal bed of bad hydraulic permeability.
It is to bore a series of single slip castings on ground for the osmotic grouting method of horizon mining region closing curtain constructionHole, slip casting hole depth is reached at oil shale layer base plate, and the grout mixing that slip casting pitch of holes should meet adjacent holes is overlapped, finallyContinuous and closed horizon mining region closing curtain can be formed.When carrying out slip casting to single hole, should use and be segmented from bottom to topThe mode of slip casting, since oil shale base plate, using only tholepin plug, carries out segmenting slip casting.
The course of work of the invention and principle are：
The present invention is to provide a closed heating zone around oil shale in-situ production zone i.e. heat injection well and recovery wellDomain.
Arrangement fracture grouting hole and curtain-grouting hole, fracture grouting hole is in quincunx distribution, and meets the slip casting of adjacent holesSlurries mutually go here and there footpath, and hole depth reaches oil shale layer base plate.The rounded single distribution in curtain-grouting hole, adjacent single hole spacing 3m, holeThe deep 5m below oil shale layer base plate.
Closing mud i.e. fracture grouting slurries are poured into fracture grouting hole, one-way valve tube is inserted to oil shale layer base plate,Grouting serous fluid to be cleaved is set in one-way valve tube, is inserted into slip casting core pipe in one-way valve tube, carries out slip casting.Work as slurry pressureDuring more than oil shale in-situ vertical stratification direction tension, slurries are rived in oil shale layer and entrance crack, form floor spacerConfining bed.Same method can form the heat-insulated confining bed of top board.
After top board, floor spacer confining bed is completed, the construction that curtain is closed in horizon mining region is carried out, single hole is appliedMan-hour, in the curtain-grouting hole under enter grouting pipe, using only tholepin plug segmenting slip casting from bottom to top, by curtain-grouting slurries fromGrouting pipe injects 5-1 sections, treats after the completion of 5-1 sections of injection, starts 5-2 sections of slip casting, until 5-n sections.After the completion of single hole construction,(construction ultimately forms horizon mining region closing curtain to carry out other curtain-grouting holes again.
After the completion of above step, that is, the heat-insulated closed area of oil shale in-situ exploitation is established, the region can carry out oily pageThe follow-up work of rock in-situ retorting.
Beneficial effects of the present invention：The present invention provides a closed heating region for oil shale underground in situ exploitation,Enter for blocking production zone longitudinal direction underground water, heat scatters and disappears and horizontal direction underground water enters and oil gas and by-product streamGo out.
Brief description of the drawings
Fig. 1 is the system enclosure method schematic diagram of the embodiment of the present invention.
Fig. 2 is the plane well location layout drawing of the embodiment of the present invention.
Fig. 3 is top board, the floor spacer confining bed construction technology figure of the embodiment of the present invention.
Fig. 4 is the horizon mining region closing curtain construction process figure of the embodiment of the present invention.
Specific embodiment
Refer to shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, be the first embodiment of the present invention, the obturator that the present embodiment is related toSystem is made up of the heat-insulated confining bed of top board, floor spacer confining bed and horizon mining region closing curtain.
Need to block that underground water enters and heat scatters and disappears on longitudinal direction；Need to block underground water entrance and oil gas in horizontal directionAnd byproduct is reserved.
Shown according to geologic information, oil shale layer buried depth is 64~72m, belong to weak water penetration stratum stratum more.The oily page of delineationRock production zone is 30m × 30m square areas.
According to the weak water penetration property on stratum, the construction of the heat-insulated confining bed of top board and floor spacer confining bed is first carried out.AdoptConstructed with fracture grouting method, slip casting bore dia 80mm, hole depth 75m, through oil shale layer.Carried out by quincunx in production zoneCloth hole, distance between borehole 2.5m.Using protrusive grouting method.Grouting with plunger is：Drilling-slip casting-cleaning bottom of hole-drilling-slip casting.Drilling to 61m places, under enter stop grouting plug, carry out perforation slip casting, 2.5~3MPa of grouting pressure, material is modified rubber cement, also may be usedThink nano modification superhigh tenacity cement-base composite material.After the completion of top board slip casting, cleaning bottom of hole drilling is carried out, at drilling to 75m, underEnter stop grouting plug, perforation slip casting is carried out to base plate.
After the completion of the heat-insulated confining bed of top board and floor spacer confining bed fracture grouting, level is formed using permeation grouting method and is openedClose curtain, slip casting bore dia 80mm, hole depth 80m, to oil shale layer base plate in exploiting field domain.Injected hole is carried out along production zone peripheryCloth hole, distance between borehole 1m.During single hole mortar depositing construction, using retrusive segmenting slip casting method from bottom to top, segmentation distance is 8m,1~1.5MPa of grouting pressure, injecting paste material is fast solidifying type polymer cement waterproof slurry.
After the completion of closed system construction, water yield is from 19m in production zone3/ d drops to 1m3Within/d, oil shale in-situProduction practice is successfully carried out and output shale oil, it was demonstrated that the method can provide the anti-of heat-insulated closing for oil shale in-situ production practiceRegion is answered, thermal loss, underground water entrance and the outflow of oil gas and byproduct is reduced.
Refer to shown in Fig. 1, Fig. 2, Fig. 3 and Fig. 4, be the second embodiment of the present invention, the obturator that the present embodiment is related toSystem is made up of the heat-insulated confining bed of top board, floor spacer confining bed and horizon mining region closing curtain.
Compared with the Coal Gasification of ground, underground gasification need not be by coal mining to ground, but coal seam is carried out in undergroundGasification, also would not on the ground produce gangue or coal ash to account for the problem that firming ground, dust and fine particulates pollute air, phaseYing Di, hazardous trace elements can increase the risk of underground water pollution in underground in coal ash.For reduce coal ash and with coal ash in be harmful toPollution of the element to groundwater environment, therefore need in advance for underground coal gasification(UCG) provides a resistant-walled production zone.
Shown according to geologic information, somewhere coal seam buried depth is 41.2~47.0m, stratum underground water is on the high side, draw a circle to approve mining areaDomain is 50m × 50m.
According to the weak water penetration property on stratum, the construction of the heat-insulated confining bed of top board and floor spacer confining bed is first carried out.AdoptConstructed with fracture grouting method, slip casting bore dia 80mm, hole depth 50m, through coal seam.In production zone cloth is carried out by quincunxHole, distance between borehole 2.5m.Using protrusive grouting method.Grouting with plunger is：Drilling-slip casting-cleaning bottom of hole-drilling-slip casting.BoreProceed at 39m, under enter stop grouting plug, carry out perforation slip casting, 2.5~3MPa of grouting pressure, material is modified rubber cement, it is also possible toIt is nano modification superhigh tenacity cement-base composite material.After the completion of top board slip casting, carry out cleaning bottom of hole drilling, at drilling to 50m, under enterStop grouting plug, perforation slip casting is carried out to base plate.
After the completion of the heat-insulated confining bed of top board and floor spacer confining bed fracture grouting, level is formed using permeation grouting method and is openedClose curtain, slip casting bore dia 80mm, hole depth 54m, to seat earth in exploiting field domain.Injected hole carries out cloth along production zone peripheryHole, distance between borehole 1m.During single hole mortar depositing construction, using retrusive segmenting slip casting method from bottom to top, segmentation distance is 8m, noteSlurry 1~1.5MPa of pressure, injecting paste material is fast solidifying type polymer cement waterproof slurry.
After the completion of closed system construction, water yield is from 30m in production zone3/ d drops to 1m3Within/d, coal underground gasChemical industry skill is successfully carried out and output coal bed gas, it was demonstrated that the method can provide the reaction zone of heat-insulated closing for coal underground gasifying technologyDomain, reduces the pollution of coal ash and harmful element to groundwater environment.