A kind of determination method of shale oil gas " dessert area " organic carbon content lower limitTechnical field
The present invention relates to the evaluation method technical field of petroleum exploration and development, and in particular to a kind of shale oil gas " dessert area "The determination method of organic carbon content lower limit.
Background technology
As oil-gas exploration and development is developed from conventional oil gas reservoir to unconventionaloil pool, shale oil gas is increasingly becoming oil-gas explorationThe key areas of exploitation.China's shale oil gas stock number is very big, and shale gas mining resources amount is about 12 tcms, shale oil(Chinese Academy of Engineering, 2012), shale oil-gas exploration potentiality to be exploited is big more than 200,000,000,000 tons for mining resources amount.In shale oil-gas explorationIn exploitation, under the conditions of current economic technology, the region that can obtain commercial oil and gas flow is referred to as " dessert area ", and organic carbon content is controlShale oil-production capacity processed and the key parameter in preferred " dessert area ", are also the material base of shale Oil-gas source.
Under DIFFERENT DEPOSITIONAL ENVIRONMENTS there is very big difference in the shale feature of formation, anabolie process, therefore, cause differentlyThere is very big difference in the shale petroleum geologic conditions in area.Shale oil and gas production not only has relation with organic carbon content, while receivingThe state modulators such as machine matter evolution level (i.e. reflectance of vitrinite Ro), porosity, hydrocarbon saturation, several key parameter synthesisControl action is risen to shale oil and gas production, but its relation there is no people to conduct a research.
Generally, shale oil and gas production and its organic carbon content correlation.When maturity of organic matter is oneWhen determining in scope, organic carbon content have to be larger than certain value, could obtain business oil and gas production.Both at home and abroad according to the condition of production,The shale organic carbon content difference for being obtained in that business oil and gas production for empirically speculating is very big, in the range from 0.5%-5%,Shale oil gas " core space " drilling well determined according to this wide in range organic carbon content lower limit obtains the general of business oil and gas productionRate is about 50%, and urgent need will determine the organic carbon content lower limit in shale oil gas " dessert area " using suitable accurately method and technologyValue, instructs shale oil-gas exploration development deployment, improves shale oil gas evaluation precision and obtains the probability of business oil and gas production.
At present, determine the method and technology of shale oil gas " dessert area " organic carbon content lower limit, be according to knowhowSpeculate with similar area and obtain, but the shale oil gas features as poor geologic condition of different regions is not very big, and organic carbon content lower limit is also poorIt is very not big, therefore, in the most successful north America region of shale oil-gas exploration and development, according to the page that knowhow and similar area push awayThe organic carbon content lower limit of shale oil gas " dessert area " is 2%-5%, and shale oil gas " the dessert area " determined in China hasMachine carbon content lower limit is 0.5%-3%.According to knowhow and the method for similar area contrast, i.e., artificial experience, it is determined that pageShale oil gas " dessert area " organic carbon content lower limit, inaccurate, error is big, no theoretical foundation.Organic carbon content lower limit value differenceIt is not big, it is to cause the main original that current shale oil gas " dessert area " error of quality appraisement is big, acquisition business oil and gas production well success rate is littleTherefore one.The method that there is no determination shale oil gas " dessert area " the organic carbon content lower limit of theoretical foundation.
The content of the invention
The invention aims to overcome cannot accurately determine present in prior art shale oil gas " dessert area " to haveA kind of deficiency of machine carbon content lower limit, there is provided determination method of shale oil gas " dessert area " organic carbon content lower limit.
In order to achieve the above object, the invention provides a kind of shale oil gas " dessert area " organic carbon content lower limit is reallyDetermine method, it is comprised the following steps：
Step A：The system that area's interval of interest is studied by determining and/or being calculated shale oil gas " dessert area " is cored directlyThe maturity of organic matter Ro of well core analysis, organic carbon content TOC, porosity POR, water saturation Sw, hydrocarbonaceous porosity Ph,And all systems are cored the final produced quantity EUR of oil gas of all horizontal wells in straight well certain distance；
Step B：Calculate the mean value Ro of the maturity of organic matter Ro of straight well of coring per port systemAveragely, and take per port systemThe mean value EUR of the final produced quantity EUR of the oil gas of all horizontal wells in heart straight well certain distanceAveragely, with RoAveragelyFor abscissa,EURAveragelyMap for ordinate, as shown in Fig. 2 final with the lowest economic technology oil gas of the horizontal well of the research area interval of interestProduced quantity EUR values are boundary, it is determined that obtaining minimum Ro values Ro_limt of business oil and gas production；
Step C：Cored the maturity of organic matter Ro and water saturation Sw data of straight well core analysis using system, with RoIt is ordinate mapping for abscissa, Sw, as shown in figure 3, making the enveloping outer enclosure of all reasonable datas in figure, some Ro is bigIt is Ro >=a% conditions in a values of Ro_limt are vertical with transverse axis and value Sw_a of the corresponding Sw of point that intersect with enveloping outer enclosureUnder, the water saturation higher limit of obtainable business oil and gas production；
Step D：Selecting system is cored a%≤Ro in straight well core analysis data<(a+b) water saturation Sw of % and containHydrocarbon porosity Ph data, with Ph as abscissa, Sw be ordinate mapping, as shown in figure 4, making all reasonable datas in figureOutward, interior envelope and intermediate value line, take what the value that Sw is Sw_a intersected respectively perpendicular to the longitudinal axis with outer, interior envelope and intermediate value linePoint, corresponding Ph values are respectively Ph3, Ph1, Ph2；
Step E：Selecting system is cored a%≤Ro in straight well core analysis data<(a+b) the hydrocarbonaceous porosity Ph of % and haveMachine carbon content TOC data, with TOC as abscissa, Ph be ordinate mapping, as shown in figure 5, making all reasonable datas in figureOuter, interior envelope and intermediate value line, the value that Ph is respectively Ph3, Ph1, Ph2 is taken, perpendicular to the longitudinal axis and respectively with outer, interior envelopeThe point intersected with intermediate value line, corresponding TOC values are respectively TOC3, TOC1, TOC2, take the minimum in TOC3, TOC1, TOC2 threeValue is used as a%≤Ro<(a+b) in the range of % TOC lower limit.
Specific embodiment of the invention, it is preferable that above-mentioned shale oil gas " dessert area " organic carbon content lower limitThe determination method of value also includes step F：Repeat step B-E, it is determined that in the range of difference Ro shale oil gas " dessert area " organic carbonContent TOC lower limit.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step AIn, the system straight well core analysis of coring for studying area's interval of interest is using the whole straight wells of research area's interval of interest, and to everyMouth straight well carries out at a certain distance boring sample and is analyzed.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step AIn, the horizontal well cored in the corresponding certain distance of straight well with system is little or substantially not apart from the change of interior geologic parameter at thisBecome, oil and gas production difference is mainly derived from the horizontal well of engineering factor, the distance is 2km-3.5km for marine bed,It is 1.5km-2.5km for Continental Facies Stratigraphy.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step AIn, rock core maturity of organic matter Ro is determined according to reflectance of vitrinite assay method in sedimentary rock (SY/T 5124-2012)Obtain；Rock core organic carbon content TOC is determined according to the measure (GB/T 19145-2003) of total organic carbon in sedimentary rockArrive；Core porosity POR is determined according to GRI (Gas research institute) shale porosity measurement methodsArrive；Rock core water containing saturability Sw is determined according to rock profit saturation degree distillation apparatus calibration steps (SY/T 6811-2010)Obtain；The hydrocarbonaceous porosity Ph of rock core is calculated with the product of core porosity POR by rock core hydrocarbon saturation, wherein rock core hydrocarbon saturation is calculated by the difference of rock mesopore volume and aqueous volume；Horizontal wellThe final produced quantity EUR of oil gas is obtained according to the production of hydrocarbons data of research area's development time longer producing well.Above-mentionedShale oil gas " dessert area " organic carbon content lower limit determination method in, it is preferable that in step B, with RoAveragelyFor horizontal strokeCoordinate, EURAveragelyLinear coordinate system is used for ordinate mapping.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step BIn, the final produced quantity EUR values of lowest economic technology oil gas of the horizontal well are by economic technology condition instantly, in the researchProduction cost, tax revenue, rate of return on investment factor are considered in the range of area's interval of interest, the minimum business oil gas for calculating tires outMeter yield.Those skilled in the art can be oily to the lowest economic technology for studying the horizontal well of area's interval of interest according to actual conditionsThe final produced quantity EUR values of gas are determined.Determined by the final produced quantity EUR values of lowest economic technology oil gas and obtain business oil gasThe Ro lower limits of yield, hydrocarbon source rock Ro does not have extraction value less than the lower limit.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step CIn, with Ro as abscissa, Sw for ordinate mapping use linear coordinate system.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step CIn, a%≤Ro<(a+b) scope of the b in % is (a+0.1)≤b≤(a+0.3).The hydrocarbon source rock of research area's interval of interest is organicMatter maturity research range a%≤Ro<(a+b) % should not be too wide, and general range is advisable for 0.1%-0.3%, can suitably relax.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step DIn, with Ph as abscissa, Sw for ordinate mapping use linear coordinate system.Outward, interior envelope is data distribution envelopeIn line parallel to the longitudinal axis is done with a certain transverse axis value, hand over two points, the big direction intersection point of longitudinal axis value to be located with outer, interior envelopeEnvelope is enveloping outer enclosure, and remaining one is interior envelope；Intermediate value line is perpendicular to the line and outer, interior envelope phase of enveloping outer enclosureHand over, the intermediate value line of two intersection points；Ph3 is the abscissa Ph values with enveloping outer enclosure intersection point, and Ph1 is the horizontal seat with interior envelope intersection pointMark Ph values, Ph2 is the abscissa Ph values with intermediate value line intersection point.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step DIn, the reasonable data is to meet the data that the regularity of distribution and distribution are relatively concentrated.
In the determination method of above-mentioned shale oil gas " dessert area " organic carbon content lower limit, it is preferable that step EIn, with TOC as abscissa, Ph for ordinate mapping use linear coordinate system.TOC3 was longitudinal axis Ph3 parallel to transversal lineTransverse axis T OC value corresponding with the intersection point of enveloping outer enclosure, TOC1 was longitudinal axis Ph1 parallel to the intersection point pair of transversal line and interior envelopeThe transverse axis T OC value answered, TOC2 was longitudinal axis Ph2 parallel to transversal line transverse axis T OC value corresponding with the intersection point of intermediate value line.
In the present invention, the principle of the determination method institute foundation of organic carbon content lower limit is：When hydrocarbon source rock reaches necessarilyShale oil gas could be formed after maturity, so shale oil gas " dessert area " must be on certain Ro (Fig. 2)；Shale series of strataThe oil gas of generation just starts to discharge full of behind its own space, and shale series of strata increase with Ro, and Sw reduces, so, it is differentCorresponding Sw upper limits difference (Fig. 3) of Ro；The exploitation of shale oil gas economic technology depends primarily on oil-containing tolerance therein, i.e., hydrocarbonaceous holePorosity, hole includes organic hole and inorganic hole, and organic hole increases as Ro increases, and inorganic hole is with Ro increasesReduce, the two contribution of superposition to hydrocarbonaceous hole has certain limit, so, it is corresponding hydrocarbonaceous using the Sw upper limits in Ro certain limitsPorosity, it is contemplated that different aperture type and evolution condition (Fig. 4)；According to the corresponding TOC lower limits of different hydrocarbonaceous porositys, takeThe minimum of a value of the TOC lower limits determined in the range of certain Ro is its lower limit (Fig. 5).
The determination method of shale oil gas " dessert area " the organic carbon content lower limit that the present invention is provided, is cored directly using systemMethod of the static geologic parameter of well core analysis in combination with the horizontal well performance creation data of correspondence, it is considered to influence factor moreComprehensively；The Ro lower limits for obtaining business oil and gas production are determined by economic technology EUR yield, is set up with economic benefit and is contacted, selected" dessert area " TOC for going out more tallies with the actual situation；It is determined that during TOC lower limits, it is contemplated that Sw, POR in the range of certain Ro etc.Factor, can more embody actual production governing factor；Give " the dessert area " that business oil and gas production is obtained in the range of certain RoTOC lower limits, the selection for shale oil gas evaluation of priorities exploration and development area provides foundation.It is true with the artificial experience of current basisThe method for determining shale oil gas " dessert area " TOC lower limits is compared, and the method for the present invention has theoretical foundation, and different Ro areas determineTOC lower limits it is different, more accurately, it is to avoid according to artificial experience value in prior art, do not consider Ro to TOC lower limitsAffect, and the error brought.
Description of the drawings
Fig. 1 is shale oil gas " dessert area " the organic carbon content lower limit determination side of a specific embodiment of the present inventionThe flow chart of method.
Fig. 2 is that shale oil gas " dessert area " the hydrocarbon source conditions lower limit of the present invention determines schematic diagram.
Fig. 3 is that the water saturation higher limit of shale oil gas " dessert area " the hydrocarbon source rock differing maturity of the present invention determines originalReason figure.
Fig. 4 is that the hydrocarbonaceous porosity boundary value of shale oil gas " dessert area " of the present invention determines schematic diagram.
Fig. 5 is that shale oil gas " dessert area " the organic carbon content lower limit of the present invention determines schematic diagram.
Fig. 6 is that in a specific embodiment of the present invention, shale oil gas " dessert area " hydrocarbon source conditions lower limit determinesFigure.
Fig. 7 be the present invention a specific embodiment in, shale oil gas " dessert area " hydrocarbon source rock differing maturity it is aqueousSaturation degree higher limit determines figure.
Fig. 8 is that in a specific embodiment of the present invention, the hydrocarbonaceous porosity boundary value of shale oil gas " dessert area " determines figure.
Fig. 9 is that in a specific embodiment of the present invention, shale oil gas " dessert area " organic carbon content lower limit determines figure.
Specific embodiment
In order to be more clearly understood to the technical characteristic of the present invention, purpose and beneficial effect, now to the skill of the present inventionArt scheme carry out it is described further below, but it is not intended that to the present invention can practical range restriction.
It is below a specific embodiment of the invention.
A kind of determination method of shale oil gas " dessert area " organic carbon content lower limit is present embodiments provided, such as Fig. 1 institutesShow, it is comprised the following steps：
Step A：The system that area's interval of interest is studied by determining and/or being calculated shale oil gas " dessert area " is cored directlyThe maturity of organic matter Ro of well core analysis, organic carbon content TOC, porosity POR, water saturation Sw, hydrocarbonaceous porosity Ph,And all systems are cored the final produced quantity EUR of oil gas of all horizontal wells in straight well certain distance；Wherein, rock core organic matter intoRipe degree Ro is determined according to reflectance of vitrinite assay method (SY/T5124-2012) in sedimentary rock and obtained；Rock core is organicCarbon content TOC is to determine to obtain according to the measure (GB/T 19145-2003) of total organic carbon in sedimentary rock；Core porosityPOR is determined and obtained according to GRI (Gas research institute) shale porosity measurement methods；Rock core is aqueous fullDetermine according to rock profit saturation degree distillation apparatus calibration steps (SY/T 6811-2010) with degree Sw and obtain；Rock core is hydrocarbonaceousPorosity Ph is by rock core hydrocarbon saturation and the product of core porosity POR and calculated, wherein rock core oil-containingGas saturation is calculated by the difference of rock mesopore volume and aqueous volume；The final produced quantity of oil gas of horizontal wellEUR is obtained according to the production of hydrocarbons data of research area's development time longer producing well；
Step B：Calculate the mean value Ro of the maturity of organic matter Ro of straight well of coring per port systemAveragely, and take per port systemThe mean value EUR of the final produced quantity EUR of the oil gas of all horizontal wells in heart straight well certain distanceAveragely, with RoAveragelyFor abscissa,EURAveragelyMap for ordinate, with the final produced quantity EUR values of lowest economic technology oil gas of the horizontal well of the research area interval of interestFor boundary, it is determined that obtaining minimum Ro values Ro_limt of business oil and gas production；
Step C：Cored the maturity of organic matter Ro and water saturation Sw data of straight well core analysis using system, with RoIt is ordinate mapping for abscissa, Sw, the enveloping outer enclosure of all reasonable datas is made in figure, some Ro is more than Ro_limtA values are vertical with transverse axis and value Sw_a of the corresponding Sw of point that intersect with enveloping outer enclosure, under the conditions of being Ro >=a%, can obtainBusiness oil and gas production water saturation higher limit；
Step D：Selecting system is cored a%≤Ro in straight well core analysis data<(a+b) water saturation Sw of % and containHydrocarbon porosity Ph data, wherein hydrocarbonaceous porosity Ph (referring to the percentage of total pore size volume shared by hydro carbons volume) is full for oilyWith degree and the product of porosity POR, with Ph as abscissa, Sw be ordinate mapping, make in figure all reasonable datas it is outer,Interior envelope and intermediate value line, take the point that the value that Sw is Sw_a intersects respectively perpendicular to the longitudinal axis with outer, interior envelope and intermediate value line, rightThe Ph values answered are respectively Ph3, Ph1, Ph2；
Step E：Selecting system is cored a%≤Ro in straight well core analysis data<(a+b) the hydrocarbonaceous porosity Ph of % and haveMachine carbon content TOC data, with TOC as abscissa, Ph be ordinate mapping, outer, the interior bag of all reasonable datas are made in figureWinding thread and intermediate value line, take the value that Ph is respectively Ph3, Ph1, Ph2, perpendicular to the longitudinal axis and respectively with outer, interior envelope and intermediate value lineIntersecting point, corresponding TOC values are respectively TOC3, TOC1, TOC2, take the minimum of a value conduct in TOC3, TOC1, TOC2 threeA%≤Ro<(a+b) in the range of % TOC lower limit；
Step F：Repeat step B-E, it is determined that in the range of difference Ro shale oil gas " dessert area " organic carbon content TOC lower limitsValue.
Using the method for the present embodiment, to 0.9%≤Ro in the shale oil gas of hawk beach<1.1% shale oil hydrocarbon source rock is organicCarbon lower limit is determined.
Cored rock core maturity of organic matter Ro, the organic carbon of 43 mouthfuls of straight well by determining and/or being calculated hawk beach systemContent TOC, porosity POR, water saturation Sw, hydrocarbonaceous porosity Ph, core the corresponding 3km scopes of straight well with each port systemThe EUR of interior totally 516 mouthfuls of water horizontal wells, the final produced quantity of lowest economic technology oil gas of the horizontal well of the research area interval of interestEUR values are 30,000 tons, the Ro of straight well of being cored using each port systemAveragelyIt is equal with all levels in the range of its corresponding 3kmEURAveragelyRelation, determines that hawk beach can obtain the Ro of business oil and gas productionAveragelyLower limit is 0.85% (Fig. 6), when hydrocarbon source rock Ro is less thanEconomic technology yield can not be obtained when 0.85%；Choose 0.9%≤Ro<1.1% system cores what straight well shale core was analyzedRo and Sw data opening relationships, according to the enveloping outer enclosure that all reasonable data points are made, corresponding Sw values are during Ro=0.9%32% (Fig. 7)；Choose 0.9%≤Ro<1.0% system is cored Sw and the Ph data opening relationships of the analysis of straight well shale core, is doneGo out the outer of all reasonable datas, interior envelope and intermediate value line, take Sw=32% perpendicular to Sw axles respectively with outer, interior envelope and inThe intersection point of value line, corresponding Ph values are respectively 7.7%, 2.15%, 4.9% (Fig. 8)；Choose 0.9%≤Ro<1.1% system takesThe Ph of heart straight well shale core analysis and TOC data opening relationships, make the outer of all reasonable datas, interior envelope and intermediate valueLine, takes the point that Ph is respectively 7.7%, 2.15%, 4.9%, is respectively perpendicular to the friendship of Ph axles and outer, interior envelope and intermediate value linePoint, corresponding TOC values are respectively 2.4%, 2.5%, 2.7%, take the minimum of a value of three as 0.9%≤Ro<When 1.1%, pageThe lower limit of shale oil gas " dessert area " TOC, i.e. TOC takes 2.4% (Fig. 9).
The determination method of shale oil gas " dessert area " the organic carbon content lower limit of the present embodiment, is cored straight well using systemThe static geologic parameter of core analysis is determined in combination with the horizontal well performance creation data of correspondence by economic technology EUR yieldThe hydrocarbon source rock Ro lower limits for obtaining business oil and gas production are 0.85%, are more tallied with the actual situation, and according to artificial in prior artEmpirically determined method, different people experience is different, it is determined that Ro lower limit difference it is very big；Shale increases with maturity, aqueousSaturation degree is reduced, and the Sw upper limits using different Ro shale are different, more meet underground actual conditions, during such as Ro=0.85%, Sw=When 34%, Ro=0.9%, Sw=32%, do not consider that Sw changes with Ro and changes in prior art；Determine shale oil gas businessOne of key factor of industry Yielding ability is its hydrocarbonaceous porosity, therefore on the basis of Ro, Sw change, has been superimposed the change of PORChange, by the relation of Ph, Sw and TOC, it is determined that 0.9%≤Ro<1.1% corresponding shale oil " dessert area " TOC lower limits are2.4%, fall within the scope of area's TOC lower limits 2%-5% are succeeded in developing by artificial empirically determined North America shale oil gas, itsValue is more accurate, foundation is more abundant, meanwhile, much larger than the TOC lower limits 0.5% that Chinese expert determines.