A method for obtaining the success rate of prospective exploration zones

Abstract

This invention belongs to the field of geological research technology, specifically relating to a method for obtaining the exploration success rate of prospective geological zones. The exploration success rate S is determined by the source coefficient O, reservoir coefficient R, caprock coefficient C, and trap coefficient T. The exploration success rate determined by this invention accurately reflects the actual exploration potential and drilling risks of prospective geological zones, reducing the error between pre-drilling predictions and post-drilling results, thereby obtaining an effective and accurate evaluation of the exploration potential and exploration deployment plan for prospective geological zones.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of geological research, and particularly relates to a method for obtaining exploration success rate of a prospective zone. BACKGROUND

[0002] The prospective zone is an exploration zone in a basin which has not yet been drilled to verify its oil and gas bearing property, and the exploration success rate of the prospective zone is a direct parameter for predicting exploration risk of the prospective zone and determining whether the prospective zone is worth investing drilling work.

[0003] At present, most researchers usually directly assign the exploration success rate of the prospective zone by personal experience or expert scoring method when queuing and predicting exploration risk of the prospective zone, and the exploration success rate of the prospective zone obtained in this way cannot truly reflect the actual exploration potential and drilling risk of the prospective zone, and there is a significant error between the prediction result before drilling and the actual result after drilling, which directly affects the evaluation of the exploration potential of the prospective zone and the exploration deployment scheme.

[0004] Therefore, the present application is provided. SUMMARY

[0005] In order to make the exploration success rate of the prospective zone truly reflect the actual exploration potential and drilling risk of the prospective zone, reduce the error between the prediction result before drilling and the actual result after drilling, and obtain effective and accurate evaluation of the exploration potential of the prospective zone and the exploration deployment scheme, the present application provides a method for obtaining the exploration success rate of the prospective zone.

[0006] The present application comprises the following technical solutions.

[0007] The present application provides a method for obtaining the exploration success rate of the prospective zone, which determines the exploration success rate S by an oil source coefficient O, a reservoir coefficient R, a cap rock coefficient C and a trap coefficient T.

[0008] Further, the exploration success rate S is determined by the following formula:

[0009] S = 25 * (O + R + C + T).

[0010] Further, the method comprises the following steps.

[0011] determining the oil source coefficient O;

[0012] determining the reservoir coefficient R;

[0013] determining the cap rock coefficient C;

[0014] Determine the trap coefficient T;

[0015] The exploration success rate S is determined by the oil source coefficient O, reservoir coefficient R, caprock coefficient C, and trap coefficient T.

[0016] Furthermore, the oil source coefficient O is determined by the following formula:

[0017] O = O ex *O ef ;

[0018] Among them: O ex Indicates the presence of an oil source, O ef This indicates the effectiveness of the oil source.

[0019] Furthermore, the existence of the oil source is determined by the following formula: O ex =min{H o / H omax A o / A omax};

[0020] Wherein: H o H represents the mudstone thickness of the potential source rock strata in the depression where the prospective area is located. omax A represents the stratigraphic thickness of the potential source rock section in the depression where the prospective area is located. o A represents the area of ​​mudstone distribution in the depression where the prospective scenic area is located. omax This represents the maximum area of ​​the depression where the distant scenic zone is located.

[0021] And / or the effectiveness of the oil source is determined by the following methods:

[0022] If the prospective area is entirely within the known hydrocarbon source rock supply range, then O ef =1;

[0023] If the prospective area is partially located within the known hydrocarbon source rock supply range, then O ef =A ot / A c ;

[0024] Among them: A ot Let A be the area of ​​the intersection region between the known source rock's hydrocarbon supply range and the prospective zone. c The area of ​​the distant scenic zone;

[0025] If the prospective area is located outside the known hydrocarbon source rock supply range, then O ef =1-L ot L oc ;

[0026] Where: L oc L represents the maximum distance between the hydrocarbon supply center and the edge of the prospective zone.ot This represents the minimum distance between the edge of the prospective zone and the hydrocarbon supply edge.

[0027] Furthermore, the reservoir coefficient R is determined by the following formula:

[0028] R = R ex *R ef ;

[0029] Where: R ex R indicates the existence of a reservoir. ef This indicates reservoir effectiveness.

[0030] Furthermore, the existence of the reservoir is determined in the following manner:

[0031] If the prospective zone is entirely within the known reservoir facies zone, then R ex =1;

[0032] If the prospective zone is partially located within the known reservoir facies zone, then R ex =A rt / A c ;

[0033] Among them: A rt Let A be the area of ​​the intersection region between the known reservoir facies zone and the prospective zone. c The area of ​​the distant scenic zone;

[0034] If the prospective zone is located outside the known reservoir facies zone:

[0035] When L rt <L r Then R ex =1-L rt / L r When L rt ≥L r At that time, R ex =0.

[0036] Where: L r L is the maximum length of the reservoir facies zone within the known reservoir facies zone range. rt It is the minimum distance between the edge of the prospective zone and the edge of the known reservoir facies zone;

[0037] And / or the reservoir effectiveness is determined by the following formula:

[0038] R ef =min{H ri / H rmax ,P ri / P rmax ,K ri / K rmax};

[0039] Wherein: H ri H represents the median reservoir thickness within the prospective zone. rmax P represents the maximum reservoir thickness within a known reservoir facies zone. ri P represents the median porosity of the reservoir within the prospective area. rmax K represents the maximum porosity of the reservoir within a known reservoir facies zone. ri K represents the median permeability of the reservoir within the prospective area. rmax The maximum permeability of the reservoir within the known reservoir facies zone.

[0040] Furthermore, the reservoir thickness mid-range number within the prospective zone is determined by the following formula:

[0041] H ri =(H rimin +H rimax ) / 2;

[0042] Wherein: H rimin H represents the minimum reservoir thickness within the prospective zone. rimax This represents the maximum reservoir thickness within the prospective area.

[0043] And / or the reservoir porosity mid-range number within the prospective zone is determined by the following formula:

[0044] P ri =(P rimin +P rimax ) / 2;

[0045] Where: P rimin P represents the minimum reservoir porosity within the prospective zone. rimax This represents the maximum porosity of the reservoir within the prospective area.

[0046] And / or the reservoir permeability mid-range number within the prospective zone is determined by the following formula:

[0047] K ri =(K rimin +K rimax ) / 2;

[0048] Where: K rimin K represents the minimum reservoir permeability within the prospective area. rimax This represents the maximum permeability of the reservoir within the prospective area.

[0049] Furthermore, the capping coefficient C is determined by the following formula:

[0050] C = C ex *C ef ;

[0051] Where: C exC represents the probability that a caprock facies zone exists at the location of the prospective area. ef This indicates the probability that the cap layer at the location of the prospective zone has effective sealing capability;

[0052] Preferably, the probability that a caprock facies zone exists at the location of the prospective area is determined in the following manner:

[0053] If the prospective area is entirely within the known cover facies zone, then C ex =1;

[0054] If the distant field zone is partially located within the known cover facies zone, then C ex =A ct / A c ;

[0055] If the prospective area is located outside the known cover facies zone:

[0056] When L cc <L c Then C ex =1-L cc / L c ;

[0057] When L cc ≥L c At that time, C ex =0.

[0058] Among them: A ct Let A be the area of ​​the intersection region between the known caprock facies zone and the prospective zone. c The area of ​​the distant scenic zone; L c Let L be the maximum length of the caprock facies zone within the known caprock facies zone range. cc It represents the minimum distance between the edge of the prospective zone and the edge of the cover facies zone;

[0059] The probability that the cap layer at the location of the prospective zone has effective sealing capability is determined by the following formula:

[0060] C ef =min{H ci / H cmax ,P cmin / P ci ,K cmin / K ci};

[0061] Wherein: H ci H represents the median thickness of the cap layer within the distant viewing area. ci =(H cimin +H cimax ) / 2, H cimin H represents the minimum thickness of the cap layer within the distant viewing area.cimax H represents the maximum thickness of the cap layer within the distant viewing area. cmax P represents the maximum thickness of the caprock within a known caprock facies zone. cmin P represents the minimum porosity of the caprock within a known caprock facies zone. ci P represents the median porosity of the caprock within the prospective scenic area. ci =(P cimin +P cimax ) / 2, P cimax P represents the maximum porosity of the caprock within the prospective viewing area. cimin K represents the minimum porosity of the caprock within a known caprock facies zone. ci K represents the median permeability of the caprock within the prospective scenic area. ci =(K cimin +K cimax ) / 2, K cimin K is the minimum permeability of the reservoir within a known caprock facies zone. cimax K represents the maximum permeability of the caprock within the prospective area. cmin The minimum permeability of the reservoir within the known caprock facies zone.

[0062] Furthermore, the closure coefficient T is determined by the following formula:

[0063] T = T ex *T ef ;

[0064] Wherein: T ex For the existence of a closed loop; T ef For the effectiveness of the trap;

[0065] Preferably, the existence of the trap is determined in the following manner:

[0066] If the prospective area is within the 3D seismic coverage area, then T ex =1;

[0067] If the distant viewing area is within the coverage area of ​​two-dimensional seismic activity, then T ex =min{1 / X1,1 / X2};

[0068] Where: X1 is the minimum spacing of two-dimensional seismic survey lines in the main survey line direction, and X2 is the minimum spacing of two-dimensional seismic survey lines in the connecting survey line direction.

[0069] And / or the effectiveness of the trap is determined by the following formula:

[0070] T ef =min{H ti / H t ,1 / (N t +1)};

[0071] Wherein: Hti H represents the median thickness of the lateral connection sealing layer for all traps within the prospective area. ti =(H timin +H timax ) / 2, H timin H represents the minimum thickness of the lateral sealing layer for all traps within the prospective area. timax H represents the maximum thickness of the lateral sealing layer for all traps within the prospective area. t H represents the median closure height of all traps within the distant viewing area. t =(H tmin +H tmax ) / 2, H tmin H represents the minimum closure height of all traps within the distant viewing area. tmax N represents the maximum closure height of all traps within the distant viewing area. t This represents the average number of faults controlling all traps within the prospective viewing area. Where: n is the number of closed loops within the prospective zone, N ti The number of faults controlling the i-th trap within the prospective area.

[0072] By adopting the above technical solution, the present invention has the following advantages:

[0073] 1. This invention is based on hydrocarbon source rocks, reservoirs, caprocks, traps and other hydrocarbon accumulation elements. It comprehensively evaluates and quickly calculates the success rate of exploration in prospective areas that approximate the actual underground conditions, thereby improving the accuracy of risk assessment in prospective areas and enhancing the effectiveness of exploration deployment plans.

[0074] 2. The success rate of prospective exploration determined by this invention truly reflects the actual exploration potential and drilling risks of prospective areas, reduces the error between pre-drilling prediction results and post-drilling actual results, and thus obtains an effective and accurate evaluation of the exploration potential of prospective areas and exploration deployment plan. Attached Figure Description

[0075] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be determined based on these drawings without creative effort.

[0076] Figure 1 This is a flowchart illustrating the implementation of a method for obtaining the success rate of prospective exploration zones in an embodiment of the present invention.

[0077] Figure 2 This is a schematic diagram of the oil source coefficient determination method in an embodiment of the present invention;

[0078] Figure 3 This is a schematic diagram of the reservoir coefficient determination method in an embodiment of the present invention;

[0079] Figure 4 This is a schematic diagram of the method for determining the cap layer coefficient in an embodiment of the present invention.

[0080] Figure 5 This is a schematic diagram of the method for determining the closure coefficient in an embodiment of the present invention.

[0081] Figure 6 This is a schematic diagram of the ORCT (Oriented Detection and Calculation) chart for the successful exploration of prospective areas, as described in this embodiment of the invention. Detailed Implementation

[0082] The following description provides many different embodiments or examples for implementing various features of the invention. The elements and arrangements described in the specific examples below are only for concise expression of the invention and are merely examples, not intended to limit the invention.

[0083] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments determined by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0084] This invention provides a method for obtaining the success rate of prospective exploration zones, such as... Figure 1 As shown, it includes the following steps:

[0085] Determine the oil source coefficient O. The oil source coefficient represents the probability that a prospective area possesses favorable oil source conditions; its magnitude depends on the existence of an oil source O. ex And oil source effectiveness O ef Two parameters, namely O = O ex *O ef The presence of oil source O ex The probability that a source rock exists in the depression where the prospective area is located is represented by O. ex =min{H o / H omax A o / A omax}, H o H represents the mudstone thickness of the potential source rock strata in the depression where the prospective area is located. omax A represents the stratigraphic thickness of the potential source rock section in the depression where the prospective area is located. o A represents the area of ​​mudstone distribution in the depression where the prospective scenic area is located. omax This represents the maximum area of ​​the depression where the prospective area is located. Oil source availability Oef This represents the probability that the prospective area has effective hydrocarbon supply capacity. If the prospective area is entirely within the known hydrocarbon supply range of the source rock, then O ef =1; If the prospective zone partially lies within the known source rock's hydrocarbon supply range (i.e., the prospective zone partially intersects with the known source rock's hydrocarbon supply range), then O ef =A ot / A c A ot Let A be the area of ​​the intersection region between the known source rock's hydrocarbon supply range and the prospective zone. c This represents the area of ​​the prospective area; if the prospective area is located outside the known source rock's hydrocarbon supply range (i.e., the prospective area does not intersect with the known source rock's hydrocarbon supply range), it is represented as O. ef =(L oc -L ot ) / L oc =1-L ot / L oc L oc L represents the maximum distance between the hydrocarbon supply center and the edge of the prospective zone. ot This is the minimum distance between the edge of the prospective zone and the hydrocarbon supply edge. For example... Figure 2 As shown, in an example from a basin in Africa, the mudstone thickness H represents the potential source layer mudstone thickness in zone A of the prospective hydrocarbon zone. o The stratigraphic thickness H of the potential source rock section in the depression where the prospective area is located is 65m. omax If it is 85m, then H o / H omax =65 / 85=0.765, the mudstone distribution area A in the depression where the prospective area zone A is located. o 3000km 2 The maximum area of ​​the depression where the A distant scenic area is located is A omax 5000km 2 Then A o / A omax =3000 / 5000=0.600, therefore, in this embodiment, the oil source existence probability of prospective zone A is O. ex =min{H o / H omax A o / A omax}=min{0.765,0.600}=0.600. In this embodiment, the prospective zone A is partially located within the known hydrocarbon source rock supply range (i.e., the prospective zone intersects with the known hydrocarbon source rock supply range), so the oil source effectiveness O ef =A ot / A c The area A of the intersection zone between the known source rock's hydrocarbon supply range and the prospective zone A is... ot 500km2 The area of ​​the A scenic zone is A c 1200km 2 In this embodiment, the oil source effectiveness of prospective zone A is O. ef =A ot / A c =500 / 1200=0.417.

[0086] Determine the reservoir coefficient R. The reservoir coefficient represents the probability that a prospective zone possesses favorable reservoir conditions; its magnitude depends on the reservoir's existence, R. ex and reservoir effectiveness R ef Two parameters, namely R = R ex *R ef The reservoir existence R ex R represents the probability that a reservoir facies zone exists at the location of the prospective prospective zone. If the prospective prospective zone is entirely within the known reservoir facies zone, then R... ex =1; If the prospective zone partially lies within the known reservoir facies zone (i.e., the prospective zone partially intersects with the known reservoir facies zone), then R = 1. ex =A rt / A c A rt Let A be the area of ​​the intersection region between the known reservoir facies zone and the prospective zone. c Let L be the area of ​​the prospective facies zone; if the prospective facies zone is located outside the known reservoir facies zone (i.e., the prospective facies zone does not intersect with the known reservoir facies zone) and L rt <L r Then it is represented as R ex =(L r -L rt ) / L r =1-L rt / L r L r L is the maximum length of the reservoir facies zone within the known reservoir facies zone range. rt L is the minimum distance between the edge of the prospective facies zone and the edge of the known reservoir facies zone; when L rt ≥L r At that time, R ex =0. Reservoir effectiveness R ef R represents the probability that the reservoir in the prospective zone has effective storage capacity. ef =min{H ri / H rmax ,P ri / P rmax ,K ri / K rmax}, where H ri H represents the median thickness of the reservoir within the prospective zone. ri =(Hrimin +H rimax ) / 2, H rimin H represents the minimum reservoir thickness within the prospective zone. rimax H represents the maximum reservoir thickness within the prospective zone. rmax P is the maximum reservoir thickness within a known reservoir facies zone. ri The reservoir porosity median number within the prospective zone is denoted as P. ri =(P rimin +P rimax ) / 2, P rimin This represents the minimum porosity of the reservoir within the prospective area.

[0087] P rimax P represents the maximum porosity of the reservoir within the prospective area. rmax K represents the maximum porosity of the reservoir within a known reservoir facies zone. ri K is the median permeability of the reservoir within the prospective zone. ri =(K rimin +K rimax ) / 2, K rimin This represents the minimum permeability of the reservoir within the prospective area.

[0088] K rimax K represents the maximum permeability of the reservoir within the prospective area. rmax This represents the maximum permeability of the reservoir within a known reservoir facies zone. Therefore,

[0089] R ef =min{(H rimin +H rimax ) / 2H rmax ,(P rimin +P rimax ) / 2P rmax ,(K rimin +K rimax ) / 2K rmax}.like Figure 3 As shown, in an example from a basin in Africa, the prospective zone A is partially located within the known reservoir facies zone (i.e., the prospective zone intersects with the known reservoir facies zone). Therefore, the reservoir existence probability R... ex =A rt / A c The area A of the intersection region between the known reservoir facies zone and the prospective zone A is known to be... rt 450km 2 The area of ​​the A scenic zone is A c 1200km 2 Then the reservoir existence R ex =A rt / A c=450 / 1200 = 0.375. In this embodiment, the reservoir effectiveness R ef =min{H ri / H rmax ,P ri / P rmax ,K ri / K rmax}, where the minimum reservoir thickness H within the prospective zone A. rimin The maximum reservoir thickness H within the A prospective zone is 18m. rimax If the reservoir thickness is 40m, then the median thickness H within the A prospective zone is... ri =(H rimin +H rimax ) / 2=(18+40) / 2=29m, the maximum reservoir thickness H within the known reservoir facies zone is given. rmax If it is 45m, then H ri / H rmax

[0090] =29 / 45=0.644; Minimum reservoir porosity P within prospective zone A rimin The maximum porosity P of the reservoir within the A prospective zone is 0.32. rimax If the value is 0.13, then the reservoir porosity median number P in the prospective zone A is... ri =(P rimin +P rimax Given that 0.32 + 0.13) / 2 = 0.225, the maximum reservoir porosity P within the known reservoir facies zone is... rmax If P is 0.44, then P ri / P rmax =0.225 / 0.44=0.511; Minimum reservoir permeability K within prospective zone A rimin The maximum permeability K of the reservoir within the A prospective zone is 0.19 md. rimax If the value is 0.33md, then A is far...

[0091] Reservoir permeability intermediate number K within the scenic area ri =(K rimin +K rimax ) / 2

[0092] = (0.19 + 0.33) / 2 = 0.26, given the maximum reservoir permeability K within the reservoir facies zone. rmax If K is 0.41, then K ri / K rmax = 0.634. Therefore, in this embodiment, the reservoir effectiveness R of prospective zone A is... ef =min{H ri / H rmax ,P ri / P rmax ,Kri / K rmax}=min{0.644,0.511,0.634}=0.511.

[0093] Determine the cap layer coefficient C. The cap layer coefficient represents the probability that the prospective area has favorable cap layer conditions, and its magnitude depends on the presence of a cap layer C. ex And cap layer effectiveness C ef Two parameters, namely C=C ex *C ef The presence of cap layer C ex C represents the probability that a cover facies zone exists at the location of the prospective area. If the prospective area is entirely within the known cover facies zone, then C... ex =1; If the prospective area zone is partially located within the known cover facies zone (i.e., the prospective area zone intersects with the known cover facies zone), then C ex =A ct / A c A ct Let A be the area of ​​the intersection region between the known caprock facies zone and the prospective zone. c Let L be the area of ​​the prospective stratum; if the prospective stratum is located outside the known cover facies zone (i.e., the prospective stratum does not intersect with the known cover facies zone) and L cc <L c Then C ex =(L c -L cc ) / L c =1-L cc / L c L c Let L be the maximum length of the caprock facies zone within the known caprock facies zone range. cc The minimum distance between the edge of the prospective facies zone and the edge of the cap phase zone; when L cc ≥L c At that time, C ex =0. Cap layer effectiveness C ef C represents the probability that the cap layer at the location of the distant viewing zone has effective sealing capability. ef =min{H ci / H cmax ,P cmin / P ci ,K cmin / K ci}, where H ci The median thickness of the cap layer within the prospective viewing area is denoted as H. ci =(H cimin +H cimax ) / 2, H cimin H represents the minimum thickness of the cap layer within the distant viewing area. cimaxH represents the maximum thickness of the cap layer within the distant viewing area. cmax P represents the maximum thickness of the caprock within a known caprock facies zone. ci The median porosity of the caprock within the prospective viewing area is denoted as P. ci =(P cimin +P cimax ) / 2, P cimin P represents the minimum porosity of the caprock within the prospective viewing area. cimax P represents the maximum porosity of the caprock within the prospective viewing area. cmin K represents the minimum porosity of the caprock within a known caprock facies zone. ci K is the median permeability number of the caprock within the prospective viewing area. ci =(K cimin +K cimax ) / 2, K cimin K represents the minimum permeability of the caprock within the prospective viewing area. cimax K represents the maximum permeability of the caprock within the prospective viewing area. cmin This represents the minimum permeability of the reservoir within a known caprock facies zone. Therefore,

[0094] C ef =min{(H cimin +H cimax ) / 2H cmax 2P cmin / (P cimin +P cimax ),2K cmin / (K cimin +K cimax )}.like Figure 4 As shown, in an embodiment of a basin in Africa, the A prospective zone is partially located within the known cover facies zone (i.e., the prospective zone intersects with the known cover facies zone). The area A of the intersection between the known cover facies zone and the prospective zone is... ct 600km 2 The area of ​​the distant scenic zone A c 1200km 2 In this embodiment, the existence of the cap layer in the A prospective area is C. ex =A ct / A c =600 / 1200 = 0.500. In this embodiment, the effectiveness C of the capping layer. ef =min{H ci / H cmax ,P cmin / P ci ,K cmin / K ci}, minimum cover thickness H within the A prospective area zone cimin The maximum thickness H of the cap layer within the A prospective area is 20m.cimax If the thickness is 45m, then the median thickness H of the cap layer within the A field area is... ci =(H cimin +H cimax ) / 2=(20+45) / 2=32.5m, given the maximum thickness H of the caprock within the caprock facies zone. cmax If it is 45m, then H ci / H cmax =32.5 / 45=0.722; Minimum porosity P of the caprock within the A prospective area zone cimin The maximum porosity P of the caprock within the A prospective area is 0.1. cimax The porosity P of the caprock within the A prospective area is 0.2. ci =(P cimin +P cimax Given that 0.2 + 0.1) / 2 = 0.15, the minimum porosity P of the caprock within the known caprock facies zone is... cmin If P is 0.09, then P cmin / P ci =0.09 / 0.15=0.600; Minimum permeability K of the caprock within prospective zone A cimin The maximum permeability K of the caprock within the prospective area A is 0.1 md. cimax If the value is 0.19 md, then the median permeability number K of the caprock within the A prospective area is... ci =(K cimin +K cimax Given that (0.1 + 0.19) / 2 = 0.145, the minimum permeability K of the reservoir within the caprock facies zone is known. cmin If K is 0.1md, then cmin / K ci =0.1 / 0.145 = 0.690. Therefore, in this embodiment, the caprock effectiveness of the A prospective zone is...

[0095] C ef =min{H ci / H cmax ,P cmin / P ci ,K cmin / K ci}=min{0.722,0.600,0.690}=0.600.

[0096] Determine the trapping coefficient T. The trapping coefficient represents the probability that the prospective area possesses favorable trapping conditions, and its magnitude depends on the existence of traps, T. ex and trap effectiveness T ef Two parameters, namely T = T ex *T ef The existence of the loop T exT represents the probability that a trap exists at the location of the prospective seismic zone. If the prospective seismic zone is within the 3D seismic coverage area, then T ex =1, if the prospective area is within the two-dimensional seismic coverage area, then T ex =min{1 / X1,1 / X2}, where X1 is the minimum spacing of 2D seismic lines along the main survey line direction, and X2 is the minimum spacing of 2D seismic lines along the connecting survey line direction. Trap effectiveness T ef T represents the probability that a trap within the prospective viewing area possesses effective trapping capability. ef =min{H ti / H t ,1 / (N t +1)}, where H ti H represents the median thickness of the lateral connection sealing layer for all traps within the prospective area. ti =(H timin +H timax ) / 2, H timin H represents the minimum thickness of the lateral sealing layer for all traps within the prospective area. timax H represents the maximum thickness of the lateral sealing layer for all traps within the prospective area. t H represents the median closure height of all traps within the distant viewing area. t =(H tmin +H tmax ) / 2, H tmin H represents the minimum closure height of all traps within the distant viewing area. tmax N represents the maximum closure height of all traps within the distant viewing area. t This represents the average number of faults controlling all traps within the prospective viewing area. Where: n is the number of closed loops within the prospective zone, N ti N represents the number of faults controlling the i-th trap within the prospective area. ti ≥0, N of the anticline trap ti =0, n>0. Therefore, like Figure 5 As shown, in an example from a basin in Africa, prospective zone A is located within the two-dimensional seismic coverage area, therefore the existence of trap T is... ex =min{1 / X1,1 / X2}, where the minimum spacing of the two-dimensional seismic survey lines in the main survey line direction X1 is 1km, and the minimum spacing of the two-dimensional seismic survey lines in the connecting survey line direction X2 is 1.2km. Therefore, in this embodiment, the existence of traps in the A prospective area zone is T. ex =min{1 / X1,1 / X2}=min{1 / 1,1 / 1.2}=min{1,0.833}=0.833. The trapping effectiveness of the Aperture Zone.

[0097] T ef=min{H ti / H t ,1 / (N t +1)}, where H is the minimum thickness H of the lateral connection sealing layer for all traps within the A prospective area. timin The maximum thickness H of the lateral connection sealing layer for all traps within the A prospective area is 17m. timax The median thickness H of the lateral connection sealing layer for all traps within the A-field zone is 28m. ti =(H timin +H timax ) / 2=(17+28) / 2=22.5;The minimum closure height H of all traps within the A-field zone. tmin The maximum closure height H of all traps within the A prospective zone is 22m. tmax The median closure height H of all traps within the A field zone is 49m. t =(H tmin +H tmax ) / 2=(22+49) / 2=35.5, then H ti / H t =22.5 / 35.5=0.634; Average number of faults in the control traps of all traps within the A prospective area.

[0098] = (1+2+1+3+1+0+1+1+0+2+3+4+1+0) / 14 = 20 / 14 = 1.429, then 1 / (N t

[0099] +1)=1 / (1+1.429)=0.412. Therefore, in this embodiment, the trapping effectiveness T of the prospective zone A is... ef =min{H ti / H t ,1 / (N t +1)}=min{0.634,0.412}=0.412.

[0100] Determine the exploration success rate S of the prospective area. Establish a quantitative chart for the exploration success rate of the prospective area (ORCT chart). The X-axis of the quantitative chart is the existence axis, and the Y-axis is the effectiveness axis. Each X-axis and Y-axis is divided into 10 equal parts, with the intersection point (0) at the 5th division of the X-axis and Y-axis. The X-axis values ​​to the left and right are 0-5, and the Y-axis values ​​to the up and down are also 0-5. This effectively divides the prospective area exploration success rate quantitative chart into 4 zones, each with an area of ​​25, for a total area of ​​100. The upper right corner area is the oil source coefficient zone O, where the X-axis value is 0. ex *5, Y-axis value is 0 ef *5, then the area of ​​region O is O ex *O ef*25. The upper left corner area represents the reservoir coefficient R zone, where the X-axis value is R. ex *5, Y-axis value is R ef *5, then the area of ​​region R is R ex *R ef *25. The lower left area represents the cap layer coefficient zone C, where the X-axis value is C. ex *5, Y-axis value is C ef *5, then the area of ​​region C is C ex *C ef *25. The lower right corner area is the closure coefficient T region, where the X-axis value is T. ex *5, Y-axis value is T ef *5, then the area of ​​region T is T ex *T ef *25. The success rate S of prospective exploration zones is represented by the sum of the areas of the oil source coefficient zone, reservoir coefficient zone, caprock coefficient zone, and trap coefficient zone, i.e., S = (O ex *O ef *25+R ex *R ef *25+C ex *C ef *25+T ex *T ef *25)=25*(O ex *O ef +R ex *R ef +C ex *C ef +T ex *T ef ) = 25 * (O + R + C + T). For example... Figure 6 As shown, in an example from a basin in Africa, the X-axis value of the oil source coefficient (O) in region A of the prospective zone is O. ex *5 = 0.600 * 5 = 3.000, the Y-axis value is 0. ef *5 = 0.417 * 5 = 2.085; the reservoir coefficient R zone X-axis value is R ex *5 = 0.375 * 5 = 1.875, the Y-axis value is R. ef *5 = 0.511 * 5 = 2.555; The X-axis value of the cap layer coefficient (C) zone is C. ex *5 = 0.500 * 5 = 2.500, the Y-axis value is C. ef *5 = 0.600 * 5 = 3.000; The X-axis value of the trap coefficient (T) region is T. ex *5 = 0.833 * 5 = 4.165, the Y-axis value is T. ef*5=0.412*5=2.060. The exploration success rate S of prospective zone A is represented by the sum of the areas of the source zone, reservoir zone, caprock zone, and trap zone. In this embodiment, the exploration success rate S of prospective zone A is S=(O ex *O ef *25+R ex *R ef *25+C ex *C ef *25+T ex *T ef *25)=25*(0.600*0.417+0.375*0.511+0.500*0.600+0.833*0.412)=25*(0.2502+0.1916+0.3000+0.3432)=27.125, that is, the exploration success rate S of prospective area A is 27.125%.

[0101] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A method of obtaining a success rate of exploration of a prospective zone, characterized in that: By obtaining exploration success rate ; wherein, is the oil source coefficient, is the reservoir coefficient; is the cap rock coefficient; is the trap coefficient; the oil source coefficient is determined by the formula: ； wherein: represents the presence of an oil source, represents the effectiveness of an oil source; The oil source presence is determined by the following equation: ; wherein: a thickness of mudstone of a potential hydrocarbon source rock section of the depression where the prospective zone is located, a formation thickness of a potential hydrocarbon source rock section of the depression where the prospective zone is located, a mudstone distribution area of the depression where the prospective zone is located, a maximum area of the depression where the prospective zone is located; and / or the oil source effectiveness is determined by: If the prospective zone is completely within the hydrocarbon supply range of known source rocks, then ; If the prospective zone is located within the known hydrocarbon source rock supply range, then ; wherein: is the area of the intersection between the source rock's range of hydrocarbon supply and the prospective play fairway, is the area of the prospective play fairway. If the prospective zone is located outside the known hydrocarbon source rock hydrocarbon supply range, then ; wherein: is the maximum distance between the hydrocarbon supply center and the prospective belt edge, is the minimum distance between the prospective belt edge and the hydrocarbon supply edge.

2. The method for obtaining the success rate of prospective exploration zones as described in claim 1, characterized in that, the reservoir coefficient is determined by the formula: ； wherein: represents the presence of a reservoir, represents the effectiveness of a reservoir.

3. The method for obtaining the success rate of prospective exploration zones as described in claim 2, characterized in that, the reservoir existence is determined by: If the prospective zone is completely within the range of the known reservoir facies belt, then ; If the prospective zone is located within the range of a known reservoir facies belt, then ; wherein: is the area of the intersection between the known reservoir fairway extent and the prospective fairway, is the area of the prospective fairway; if the prospective zone is located outside the range of known reservoir facies belts: When then when , ; wherein: is the maximum length of the reservoir facies belt within the known reservoir facies belt range, is the minimum distance between the edge of the prospective zone and the edge of the known reservoir facies belt. and / or the reservoir effectiveness is determined by: ； wherein: is the mean of the reservoir thicknesses within the belt of the prospect, is the maximum reservoir thickness within the known range of the reservoir facies belt, is the mean of the reservoir porosities within the belt of the prospect, is the maximum reservoir porosity within the known range of the reservoir facies belt, is the mean of the reservoir permeabilities within the belt of the prospect, is the maximum reservoir permeability within the known range of the reservoir facies belt.

4. The method of claim 3, wherein the prospective zone is a pay zone. 5 the reservoir thickness mean value in the prospective zone is determined by: ； wherein: is the minimum thickness of the reservoir within the prospective zone, is the maximum thickness of the reservoir within the prospective zone; and / or the reservoir porosity mean value in the prospective zone is determined by: ； wherein: is the minimum porosity of the reservoir within the prospective zone, is the maximum porosity of the reservoir within the prospective zone. and / or the reservoir permeability mean value in the prospective zone is determined by: ； wherein: Kmin is the minimum permeability of the reservoir within the prospective zone, Kmax is the maximum permeability of the reservoir within the prospective zone.

5. The method for obtaining the success rate of prospective exploration zones as described in claim 1, characterized in that, the cap layer coefficient is determined by the formula: ； wherein: represents the probability that the location of the prospective zone is in a cap facies belt, represents the probability that the cap at the location of the prospective zone has an effective capping ability; the probability that the location of the prospective zone is in a cap rock facies belt is determined by: If the prospective zone is completely within the range of the known cap rock facies belt, then ; If the prospective zone part is located within the range of the known cap rock facies belt, then ; if the prospective zone is located outside the range of known cap rock facies belts: When then ; When Time, ; wherein: is the area of the intersection between the known cap rock facies belt range and the prospective zone belt, is the area of the prospective zone belt; is the maximum length of the cap rock facies belt within the known cap rock facies belt range, is the minimum distance between the edge of the prospective zone belt and the edge of the cap rock facies belt. and / or the probability that the cap rock at the location of the prospective zone has effective sealing capacity is determined by: ； wherein: is the average thickness of the cap rock within the prospective zone, , is the minimum thickness of the cap rock within the prospective zone, is the maximum thickness of the cap rock within the prospective zone, is the maximum thickness of the cap rock for the known range of the facies belt, is the minimum porosity of the cap rock for the known range of the facies belt, is the average porosity of the cap rock within the prospective zone, , is the maximum porosity of the cap rock within the prospective zone, is the minimum porosity of the cap rock within the prospective zone, is the average permeability of the cap rock within the prospective zone, , is the minimum permeability of the cap rock within the prospective zone, is the maximum permeability of the cap rock within the prospective zone, is the minimum reservoir permeability for the known range of the facies belt.

6. The method of claim 1, wherein the prospective zone is a pay zone. 5 the trapping coefficient is determined by the formula: ； wherein: is the trap existence; is the trap effectiveness; the trap existence is determined by: If the prospective zone is located within the 3D seismic coverage, then ; If the prospective zone is located within the 2D seismic coverage, then ; wherein: is the minimum spacing of the two-dimensional seismic survey lines in the main survey line direction, is the minimum spacing of the two-dimensional seismic survey lines in the tie line direction; and / or the trap effectiveness is determined by: ； wherein: is the average of the thicknesses of the lateral butt-plugging layers of all the traps in the prospective zone, , is the minimum thickness of the lateral butt-plugging layers of all the traps in the prospective zone, is the maximum thickness of the lateral butt-plugging layers of all the traps in the prospective zone, is the average of the closure heights of all the traps in the prospective zone, , is the minimum closure height of all the traps in the prospective zone, is the maximum closure height of all the traps in the prospective zone, is the average of the number of faulted layers controlling the traps of all the traps in the prospective zone, wherein: is the number of traps in the prospective zone, is the number of faulted layers controlling the trap of the th trap in the prospective zone.

Images