Patent Publication Number: US-2007095531-A1

Title: Method of extracting hydrocarbons

Description:
CROSS REFERENCE TO RELATED APPLICATIONS  
      The present application claims the benefit of U.S. provisional applications, Ser. No. 60/730,805, filed Oct. 27, 2005, by Ian K. Rosen for METHOD OF EXTRACTING HYDROCARBONS; and Ser. No. 60/753,880, filed Dec. 23, 2005, which are hereby incorporated herein by reference in their entireties. 
    
    
     BACKGROUND OF THE INVENTION  
      The present invention is directed to a method of identifying and extracting hydrocarbons from a land formation.  
      Oil and gas hydrocarbons are found commercially below the surface of the land or water. Typically, such hydrocarbons are found in commercial quantities in “traps” of various types. These traps may include tops or caps formed of hard, dense geological material that are impermeable to seepage and restrain the hydrocarbons in underground pockets, and may include similarly formed side enclosures and/or walls forming multiple sections or compartments within the trap.  
      Typical indicators of hydrocarbon traps are source rock outflows, which may be found in valleys and flatlands, where most hydrocarbon exploration presently takes place. Also, land formations having such traps often include interior structural changes, features and/or anomalies, such as anticlines, synclines, fracturing, fragmenting, faulting, over-thrusts, horsts and grabens, which may result from movement of the geological formation and create a trap within the land formation.  
      Known methods of exploration for these traps or pockets of hydrocarbons include drilling down from above to penetrate or tap the traps of hydrocarbons and to pump the hydrocarbons out of the trap or let them pressure flow to the surface. Sometimes “slant” drilling from the top location to the perceived trap is used for environmental or technical reasons to reach a pocket that cannot be reached by drilling straight down from the top surface. A relatively new technique involves drilling down and then shifting to horizontal drilling (i.e. an “L” shaped configuration, where the horizontal component is underground) to cover a broader area in the “pay zone” and to break down honeycomb structure or configuration or other compartments in the trap or traps to increase the recovery. However, such L-style drilling is more costly than the standard vertical known method of drilling and often involves the use of narrower diameter drilling bores, which may reduce the rate of recovery of the hydrocarbons.  
      It is also known to erect drilling rigs on hills or mountains to tap possible hydrocarbon pockets in such land formations using the drilling techniques mentioned above. Land formations such as mountains may include, for example, anti-cline fold traps, stratigraphic traps and fault traps containing significant quantities of entrapped hydrocarbons. However, the construction and operation of oil rigs on mountainous and/or hilly land formations is costly and difficult due to logistical factors such as the lack of roads to and general inaccessibility of the drilling location, the depth of drilling required, and the like. Therefore, level or generally level terrain and valleys rather than mountains are more consistently and economically explored and drilled.  
      Another known method of exploration in a mountain or other rock formation includes creating passageways by chipping and blasting away at the rock or other geological matter. This method is generally used for the exploration of solid formations, such as coal, gold, silver, copper and the like, and may be used to create a large access tunnel for transportation of vehicles, trains, miners or other workers, equipment and the like.  
     SUMMARY OF THE INVENTION  
      The present invention provides a method of identifying and extracting hydrocarbons from uneven land formations such as mountains, hills and ridges. The method may include drilling generally horizontally or at an upwardly inclined angle from a surface, such as a side of a mountain or hill, or drilling vertically upward from the bottom of a surface, such as a cliff or ridge, and into a pocket or trap of hydrocarbons.  
      According to an aspect of the present invention, a method of extracting hydrocarbons entrapped in a land formation includes forming at least one passage into the land formation at an exposed surface portion of the land formation such that the passage is formed as a substantially horizontal or as an upwardly inclined passage into the land formation. The exposed surface portion is positioned vertically lower than at least a portion of the entrapped hydrocarbons. The method of extraction includes accessing the entrapped hydrocarbons with the passage, removing the entrapped hydrocarbons from the land formation via the passage, and capturing the removed hydrocarbons.  
      According to another aspect of the present invention, a hydrocarbon extraction system for extracting entrapped hydrocarbons from a land formation comprises a drilling mechanism operable to form at least one substantially horizontal or upwardly inclined passage into the land formation.  
      According to another aspect of the present invention, a method of directionally-variable seismic exploration for hydrocarbons entrapped in a land formation comprises projecting a first seismic signal into the land formation from a first location and receiving a first return signal in response to the first seismic signal. The method further comprises projecting a second seismic signal into the land formation from a second location and receiving a second return signal in response to the second seismic signal. The second location is remote from the first location, and the first and second seismic signals generally intersect within the land formation. The first and second return signals are adapted to provide information indicative of entrapped hydrocarbons within the land formation.  
      Therefore, the present invention provides a means and method of identifying and drilling into or accessing hydrocarbons within a mountain or hill from the side of the mountain or hill. The generally horizontal passage and/or an upwardly inclined passage formed in the land formation from the exposed surface portion enables the hydrocarbons to be readily removed or drained from the land formation with the assistance of gravity. The substantially horizontal passage and/or upwardly inclined passage (which allows the hydrocarbons to flow generally downwardly and out of the land formation) thus significantly reduces any pumping force that may be required to remove the hydrocarbons as compared to a vertically drilled passage that requires the hydrocarbons to be pumped upwards. Also, because the trap may be accessed at a lower portion of the trap, the present invention may, in some geographical situations, avoid drilling through a hard cap formation covering the entrapped hydrocarbons. Furthermore, a greater portion of the hydrocarbons may be removed when the passage penetrates the entrapped pool of hydrocarbons at a bottom or lower portion of the pool as compared to drilling a passage vertically into a top portion of the entrapped hydrocarbon pool.  
      These and other objects, advantages, purposes, and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       FIG. 1  is a side elevation and partial sectional view of entrapped hydrocarbons being extracted from a mountain in accordance with the method and system of the present invention;  
       FIG. 1A  is a side elevation and partial sectional view of the hydrocarbon extraction system of the present invention, showing an upwardly angled generally L-shaped passage formed in the land formation;  
       FIG. 2  is a side elevation and partial sectional view of the hydrocarbon extraction system of the present invention, showing the drilling device for drilling a passage through the land formation.  
       FIG. 3  is a side elevation and partial sectional view of a directionally-variable seismic exploration system for exploration of entrapped hydrocarbons within a land formation in accordance with the present invention;  
       FIG. 4  is a plan view of a seismic testing apparatus interface for projecting and receiving seismic signals in accordance with the present invention;  
       FIG. 5  is a plan view of another seismic testing apparatus interface for projecting and receiving seismic signals in accordance with the present invention; and  
       FIG. 6  is a schematic illustration of a three dimensional image of a rock formation entrapping hydrocarbons that may be detected by the directionally-variable seismic exploration system of the present invention. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
      The present invention will now be described with reference to the accompanying figures, wherein the numbered elements in the following written description correspond to like-numbered elements in the figures. A method of extracting hydrocarbons or a hydrocarbon extraction system  18  functions to identify and extract hydrocarbons from a land formation where the entrapped gasified or liquefied hydrocarbons  10  are generally contained as a pool  12  within a pocket or cavity or trap  14  located within a land formation  16 , such as a mountain or hill or ridge or cliff or the like. The land formation  16  includes an exterior or exposed surface portion or side  20  with the trap  14  located interior of the side  20 , such that at least a portion of the side  20  is positioned lower than or below at least a portion of the entrapped hydrocarbons  10 . A passage  22  is drilled or otherwise formed in the land formation  16  by hydrocarbon extraction system  18 . The passage  22  originates at the exposed surface portion and extends into the sides  20  of land formation  16  and penetrates the entrapped hydrocarbons  10 , whereby the hydrocarbons  10  may be released or removed through the passage  22 .  
      As shown in  FIG. 1 , passage  22  may be drilled substantially horizontally into the land formation. Further, another passage  24  may also or otherwise be drilled or otherwise formed by the hydrocarbon extraction system at an upwardly inclined angle into land formation  16  without affecting the scope of the present invention. Optionally, and as shown in  FIG. 1A , a passage  22 ′ formed by a hydrocarbon extraction system  18 ′ may have a generally horizontal or inclined passage or component  22   a ′ and may turn or angle upward inside the land formation to have a generally vertical or more inclined passage or component  22   b ′. Optionally, the passage may turn or angle directly upward, or vertically, such that the passage forms a generally L-shaped passage. The substantially horizontal or L-shaped passage  22  or  22 ′ (or upwardly inclined passage  24 ) extending into the land formation  16  from the exposed surface portion or side  20  enables the hydrocarbons  10  to be more readily removed via gravitational draining of the hydrocarbons  10  from the trap  14  within the land formation  16  and, in some geographical situations, may avoid the necessity of drilling through a hard cap  26  formation covering the entrapped hydrocarbons  10  and/or may provide the shortest drilling distance to the entrapped hydrocarbons  10 . The substantially horizontal or L-shaped passage  22 ,  22 ′ and/or upwardly inclined passage  24  also significantly reduce any pumping force that may be required to remove the hydrocarbons as compared to a conventional, vertically or substantially vertically formed passage. Furthermore, a substantial amount or a greater portion of the hydrocarbons  10  may be removed when the passage  22 ,  24  penetrates the entrapped pool of hydrocarbons at a bottom or lower portion  28  of the pool  12  as compared to drilling a passage vertically into a top portion  30  of the entrapped hydrocarbon pool  12 .  
      As noted above, the land formation  16  may include a cap  26  covering the entrapped hydrocarbons  10  contained within trap  14 . Cap  26  may cover more than one trap  14  containing hydrocarbons  10  (such as shown in  FIG. 1A ). Although shown as having exposed surface portion  20  positioned vertically below a portion of the entrapped hydrocarbons  10  (and at which passages  22 ,  24  originate), it should be appreciated, however, that, due to the multiple sloping faces or sides of the land formation or hill or mountain, other exposed surface portions or sides may exist at which passages could be formed that would still penetrate the entrapped hydrocarbons  10 , with the number of suitable exposed surface portions being dependent upon the geographical structure of the land formation  16 . Furthermore, although passages  22 ,  24  originating from a single exposed surface portion  20  are illustrated, it should be appreciated that other passages at multiple exposed surface portions about the land formation  16  could be formed in accordance with the present invention to reach the entrapped hydrocarbons  10 . Still further, although two passages  22 ,  24  are illustrated in  FIG. 1 , it should also be appreciated that only one passage need be formed in land formation  16  (such as shown, for example, in  FIG. 1A ) to extract hydrocarbons  10  in accordance with the present invention, with such a passage formed as either a substantially horizontal passage or as an upwardly inclined passage or as a generally L-shaped passage, depending on the particular land formation and/or location of the trap within the land formation and/or accessibility to the exposed surface or side of the land formation and/or the like.  
      Although land formation  16  is illustrated as a mountain, it should be appreciated that other land formations may contain entrapped hydrocarbons that may be removed by the method of extraction of the present invention. Many above-ground land formations, including but not limited to ridges, hills, cliffs, and the like, have many of the characteristics and phenomena that are indicative of what is presently sought underground. Such land formations may include entrapped hydrocarbons within the land formation and may have at least one exposed surface portion or side or wall or face that has a portion located at or lower than or below a portion of the entrapped hydrocarbons, such that the hydrocarbons may be desirably removed using the presently described extraction method. Such land formations generally include sides or walls or other exposed surface portions formed by natural causes, such as erosion or tectonic events. It should also be appreciated, however, that land formations containing entrapped hydrocarbons may be provided with exposed surface portions positioned vertically lower than a portion of the entrapped hydrocarbons as a result of human made efforts or causes. For example, a valley or depression or other exposed exterior surface may be formed or enlarged at an adjacent mountain side or other land formation by blasting and/or removal of the rocks, soil, and/or minerals located at the land formation. Thus, the present invention teaches a novel way to identify and exploit such above-ground indicators of potential hydrocarbon opportunities.  
      As previously noted, passage  22  and/or  24  is/are formed by hydrocarbon extraction system  18  drilling into land formation  16  to remove the entrapped hydrocarbons  10 , where the passage or passages may be formed as a generally horizontal passage  22  extending into the trap or as a passage  24  extending at an upwardly inclined angle into the trap. The spud-in, or initial penetration into mountain or land formation  16  to form passages  22 ,  24  may be accomplished using known oil and gas exploration systems, such as by drilling equipment or the like. For example, a rotary drill bit that is between about two and 40 inches in diameter may be used to form a circular or tubular passage through the land formation. Such a rotary drill bit is commonly used in essentially downward or vertically-drilled oil and gas exploration, in which oil and gas and/or other flowable substances are lifted or pumped up and out of the land formation. The passage may also be formed, in total or in part, by blasting, high pressure eroding, or some combination thereof. By way of example, and as shown in  FIG. 2 , hydrocarbon extractor system  18  may include a drilling mechanism  31 , which is operable to form passages, such as a horizontal passage  33  into land formation  16 . The passage  33  is shown as a partial passage and, upon completion of the drilling process, the passage formed by drilling mechanism  31  may be substantially similar to passage  22  and/or  24  illustrated in  FIG. 1  or to passage  22 ′ of  FIG. 1A .  
      As noted, passages  22 ,  22 ′,  24  penetrate the entrapped hydrocarbons  10  beneath cap  26 , where cap  26  may be a solid rock formation, or the like, that entraps the hydrocarbons  10  within land formation  16 . Due to the hard, dense geological structure of cap  26 , cap  26  provides greater resistance to the formation of a passage to the trap from above the trap. Thus, it should be appreciated that the formation of passages  22 ,  22 ′,  24  into trap  14  beneath cap  26  is more readily accomplished as compared to drilling a passage downward from above and through cap  26 , and thus may be accomplished with less wear and tear to the drilling equipment and/or by using lower cost equipment. Although not illustrated, the caps at traps within land formations may also include geological structures forming side enclosures extending about the sides or around the entrapped hydrocarbons, thereby necessitating that the passage be formed through such side enclosures, in order to fully or substantially access the hydrocarbons within the trap. The geological formation of the land formation may be such that the side enclosures are either of thinner formation as compared to the top cap portion and/or are located closer to the outer surface of the land formation. In such situations, the drilling method of the present invention may access a lower portion of the trap to drain the hydrocarbons from the trap and without having to form one or more passages through the cap structure. Thus, access and substantial draining of the hydrocarbons from such a trap may be more readily accomplished using the hydrocarbon extraction method of the present invention.  
      As illustrated in  FIG. 1 , land formation  16  may also include additional geological wall formations  32  within trap  14  that subdivide the trap  14  and the entrapped hydrocarbons  10  therein into separate sections  34 ,  36 . Although only one such geological wall formation  32  is shown extending in a generally vertical manner, it should be appreciated that land formations containing entrapped hydrocarbons may include additional such geological walls extending at various angles within the trap, whereby the hydrocarbons become entrapped within a honeycomb like structure. As shown in  FIG. 1 , passage  22  may extend through sections  34 ,  36  of trap  14  and thus may be adapted to be used to remove the hydrocarbons  10  from both sections  34 ,  36  of trap  14 . Also, or otherwise, the passage may be formed at a lower or bottom portion of the trap (such as shown with passage  24 ) to substantially access and drain both sections or compartments of the trap. It should be appreciated that a conventional, generally vertical passage penetrating a trap from above may only be useful in removing the entrapped hydrocarbons from a single section of such a trap, thus leaving a significant portion of the hydrocarbons within the land formation or necessitating the construction of additional generally vertical passages to penetrate the other sections.  
      As shown in  FIG. 1A , the land formation  16  may include more than one trap of entrapped hydrocarbons  10 . Although only two traps  14 ′ are illustrated, it should be appreciated that a land formation may include a number of these traps. As shown in  FIG. 1A , a cap  26  covers the two traps  14 ′, including a lower trap  35  and an upper trap  37 . To access the entrapped hydrocarbons  12  in both traps  35 ,  37 , passage  22   a ′ of passage  22 ′ is formed or drilled to extend in a generally horizontal direction into land formation  16  and then is formed or drilled to turn or angle generally upward (to form passage  22   b ′) to extend through a bottom or lower portion  35   a  of lower trap  35 . Passage  22   b ′ may be further formed or drilled to exit an upper portion  35   b  of lower trap  35  and then continue through a bottom or lower portion  37   a  of upper trap  37 . Thus, the hydrocarbons entrapped in both traps  35 ,  37  may be accessible and drained or extracted via the generally L-shaped passage  22 ′.  
      The entrapped hydrocarbons  10  positioned within the trap or traps and above or at least partially above the passage  22 ,  22 ′,  24  often include potential or stored energy due to their vertical elevation relative to the passage  22 ,  22 ′,  24 . This feature, together with the generally horizontal orientation of the passage or the downward slope of the passage from the trap to the exposed surface portion  20 , significantly aids in the removal of the hydrocarbons  10  from the trap or traps by natural gravitational draining. Thus, the method of the present invention includes controlled, gravitational extraction and/or downward flow of hydrocarbons from a land formation, which is different from prior methods of extraction for both solids and flowable substances.  
      Furthermore, the pocket of entrapped hydrocarbons  10 , which may be in a gasified (“gas”) or liquefied (“oil”) state, may be pressurized relative to atmospheric pressure at the exposed surface portion  20 . In such an application, the pressurized hydrocarbons  10  may further aid in the discharge of the hydrocarbons  10  through passages  22 ,  22 ′,  24 .  
      Optionally, and as shown in  FIGS. 1 and 1 A, hydrocarbon extraction system  18 ,  18 ′ may include a pumping system or mechanism  38  to further assist the removal of hydrocarbons  10  from the land formation  16 . Pumping system  38  may comprise any known type of pumping unit, such as the types typically used in vertical hydrocarbon extraction, such as a downhole sucker rod pump system or the like, that is modified for operating in connection with the generally horizontal or L-shaped or upwardly inclined passages  22 ,  22 ′,  24 . As noted, the pumping forces required to remove the entrapped hydrocarbons  10  through passages  22 ,  22 ′,  24  would be significantly lower as compared to pumping the hydrocarbons out of a vertical passage. As such, lower cost pumping equipment or other extracting equipment may be utilized to remove the hydrocarbons.  
      Optionally, hydrocarbon extraction system  18 ,  18 ′ may include a conduit or casing  40 ,  40 ′,  42  within and along passage or passages  22 ,  22 ′,  24 , respectively, to assist in extracting the hydrocarbons through the passage or passages. Such casings are typically implemented in conventional downward or vertical drilling techniques and are known in the field of oil and gas hydrocarbon extraction. Casings  40 ,  40 ′,  42  may be formed of a steel tubing and may include perforated sections to allow the entry of the hydrocarbons into the casings  40 ,  40 ′,  42 . Although not shown, a casing may also utilize liners extending out in a “T” fashion from the casings at various intervals, where such liners are also known in the field of oil and gas hydrocarbon extraction. Depending on the geological strata through which such a casing extends, cement may also be distributed between the earthen wall of the passage and the outer surface of the casing, with such a cementing process being known in the art and intended to provide mechanical support to the casing.  
      As shown in  FIGS. 1 and 1 A, hydrocarbon extraction system  18 ,  18 ′ may also include a piping system  44  employed in connection with the extraction of the hydrocarbons  10 . The piping system  44  may be formed utilizing known construction and functions to transport the released hydrocarbons, as through pipeline  46 , to a location remote from the land formation  16 , such as to a ship or containment vessel or processing facility. Alternatively, the released hydrocarbons may be captured and temporarily stored in a container located in the general area of land formation  16 .  
      In the illustrated embodiments, passages  22 ,  22 ′,  24  are formed to penetrate the entrapped hydrocarbons  10  at the lower or bottom portion of the trap or traps such that a significant portion of the hydrocarbons  10  are located vertically higher than the entrance location of the passages  22 ,  22 ′,  24  at the trap. It should be understood, however, that a passage may be alternatively formed to penetrate a trap at a middle or upper portion of the trap such that a smaller portion of the entrapped hydrocarbons are located vertically above the passage, with the present extraction method still functioning as intended within the scope of the present invention. In such applications, a pump or other extraction device may be desirable to assist in drawing the hydrocarbon from the trap.  
      It should be appreciated that generally vertical or slanted passages formed to penetrate entrapped hydrocarbons from above a trap are not as well suited to removing hydrocarbons as compared to the method and system of the present invention. Such a vertical passage, in the case of pressurized hydrocarbons, may enable a portion of the hydrocarbons to discharge from the land formation. However, when the pressure within the trap becomes substantially equalized with the atmospheric pressure, the entrapped hydrocarbons will no longer flow out of the passage without employing additional removal techniques. For example, it may be necessary to pump out the hydrocarbons or to input a pressure catalyst or volume filler, such as another gas or liquid, into the trap to force or float the hydrocarbons out of the trap. Furthermore, the removal of entrapped hydrocarbons using passages formed to penetrate traps from above are not as proficient at substantially fully evacuating the hydrocarbons as compared to the method of hydrocarbon removal of the present invention due to the hydrocarbons settling at the bottom portion of the trap and thus being distally or remotely located from the vertical passages entering the trap at the upper portion of the trap.  
      Therefore, the method and system of hydrocarbon extraction of the present invention readily enables a greater portion of entrapped hydrocarbons to be removed from a land formation with less effort as compared to conventional vertical drilling. A substantially horizontal or L-shaped passage or upwardly inclined passage extending into a land formation and originating from an exposed surface portion that is located vertically lower than at least a portion of the entrapped hydrocarbons enables the hydrocarbons to be readily removed due to the assistance of gravitational draining of the hydrocarbons from the land formation, and in some geographical situations may avoid the necessity of drilling through a hard cap formation covering the entrapped hydrocarbons. If pumping is required or desired to remove the hydrocarbons, the substantially horizontal or L-shaped passage and/or upwardly inclined passage may significantly reduce the pumping force or power needed to remove the hydrocarbons as compared to the force/power required to extract the hydrocarbons through a vertically drilled passage. Furthermore, by forming a passage that penetrates the entrapped hydrocarbons at a location beneath the upper portion of the trap, a greater percentage of the entrapped hydrocarbons may be removed as compared to passages that are formed from vertically above the entrapped hydrocarbon pool.  
      Referring now to  FIG. 3 , a directionally-variable seismic exploration system  150  is illustrated in connection with exploration and identification of entrapped hydrocarbons  110  within a land formation  116 , such as a mountain or hill or the like. Seismic exploration is known to be used for non-invasively detecting the presence of entrapped hydrocarbons within the interior of a land formation and involves projecting seismic signals, such as shock waves, into the ground and recording or detecting reflected signals (described below) that may indicate key markers for the presence of entrapped hydrocarbons. For example, and with reference to  FIG. 3 , the projected shock waves may reflect from hard, dense geological material within the mountain that forms a trap  114  about the hydrocarbons  110 .  
      Conventional seismic exploration techniques are typically conducted over a single, limited geographical location and involve projecting seismic signals, such as shock waves generated by explosions, in a generally vertically downward direction from a generally horizontal surface and recording the reflected signals that are returned in a generally vertically upward direction. Conventional seismic exploration techniques, thus, provide a limited topographical understanding of the position, size, and quantity of entrapped hydrocarbons within a land formation. The topographical information provided is related to the overall footprint of the potentially entrapped hydrocarbons and the depth from the surface to various portions of the trap.  
      In contrast, the seismic exploration system of the present invention involves projecting and receiving seismic signals generally horizontally at a side of a mountain or hill or other similar land formation. In a preferred embodiment, a directionally-variable exploration system projects and receives seismic signals from at least two separate geographic locations, with the projected signals (such as one oriented generally vertically and one oriented generally horizontally) being oriented to generally intersect within the interior of the land formation. The directionally-variable seismic exploration system is able to generate a more detailed, three-dimensional-type understanding regarding the position, size, and quantity of hydrocarbons potentially entrapped within the land formation.  
      The directionally-variable seismic exploration system  150  includes a first or generally vertical seismic testing apparatus or system  152   a , shown as being located at the top or upper portion  154  of land formation  116 , and a second or generally horizontal seismic testing apparatus or system  152   b , shown as being located on a side or exposed surface portion  155  of land formation  116 , with the second seismic testing apparatus  152   b  being positioned at a vertical height orientation that is below the first seismic testing apparatus  152   a . The first and second seismic testing apparatuses  152   a ,  152   b  are used to generate and project seismic signals  156   a ,  156   b , respectively, into the interior of the land formation  116 . In the illustrated embodiment, the first seismic testing apparatus  152   a  generates signals  156   a  that project in a generally vertically downward orientation and the second seismic testing apparatus  152   b  generates signals  156   b  that project in a generally horizontal orientation. As illustrated, the projected seismic signals  156   a ,  156   b  are oriented to generally intersect within the interior of the land formation  116  and may be targeted at particular depths and/or locations for finding and analyzing traps  114  that may indicate or entrap hydrocarbons within the land formation  116 .  
      The first and second seismic testing apparatuses  152   a ,  152   b  are also adapted to receive or detect or record return signals  158   a ,  158   b , respectively, that correspond to the projected seismic signals  156   a ,  156   b . The return signals  158   a ,  158   b  reflect or bounce off various formations or elements within the land formation, such as, for example, a trap  114 . The return signals  158   a ,  158   b , through known techniques, may be processed, as by the use of a processor or computer  160 , to provide information regarding the geological makeup and/or formation and/or size of the interior of land formation  116 . Notably, the return signals  158   a ,  158   b  may be used to generate three-dimensional data or an image  162  ( FIG. 6 ) regarding the potential position and size of a trap  114  to indicate the quantity of entrapped hydrocarbons  110  within land formation  116 .  
      As previously noted, the first and second seismic testing apparatuses  152   a ,  152   b  are positioned at remote locations from each other, such as at the top or upper portion  154  and side  155  of land formation  116 . It should be appreciated that first and second seismic testing apparatuses  152   a ,  152   b  are schematically illustrated and may incorporate various individual components and/or equipment, as described below, and may cover variously sized surface areas on land formation  116 .  
       FIGS. 4 and 5  illustrate alternative interfaces  163   a ,  163   b  for certain of the components and/or equipment of one or both of seismic testing apparatuses  152   a ,  152   b  with locations on a land formation for projecting and receiving seismic signals. As shown in  FIG. 4 , the interface  163   a  may include various shock points  164   a  for generating seismic shock wave signals, such as by detonation of explosive charges. The interface  163   a  of the seismic testing apparatus  152   a ,  152   b  includes shock points  164   a  extending in both a first axis  166  and a second axis  168  to form a “two-dimensional” testing interface grid. The seismic testing apparatus  152   a ,  152   b  includes a detecting or receiving or recording device  170   a  for receiving the reflected or returned seismic signals that bounce off or are reflected from geological formations within the land formation. Optionally, and as shown in  FIG. 5 , the interface  163   b , may include additional shock points  164   b  that extend over substantially the entire interface  163   b  to form a “three-dimensional” testing grid. The seismic testing apparatus includes a detecting or receiving or recording device  170   b  for receiving the reflected or returned seismic signals.  
      It should be appreciated that the first and second seismic testing apparatuses  152   a ,  152   b  may be constructed to have an interface having either a “two-dimensional” or a “three-dimensional” grid, as described above. It should also be appreciated that testing may be done using a single shock point to generate a single seismic wave, and that the seismic signals may be formed by different means, such as by sound or other wave signal. Furthermore, although illustrated as including only first and second seismic testing apparatuses in  FIG. 3 , directionally-variable seismic exploration system  150  may alternatively be constructed to include additional seismic testing apparatuses that project seismic signals into a land formation and record returned seismic signals. Directionally-variable seismic exploration may also involve, and such as illustrated in  FIG. 3 , forming a tunnel  172  into the land formation  116  and placing a seismic testing apparatus (not shown) into the tunnel  172  for projecting seismic signals and detecting or recording returned signals.  
      As noted above, first seismic testing apparatus  152   a  may be positioned to project seismic signals  156   a  and receive return signals  158   a  in a generally vertical orientation and second seismic testing apparatus  152   b  may be positioned to project seismic signals  156   b  and receive return signals  158   b  in a generally horizontal orientation. Two or more seismic testing apparatuses may, however, be alternatively positioned with respect to each other and with respect to a land formation to perform directionally-variable seismic exploration within the scope of the present invention. For example, one or more seismic testing apparatuses may be oriented to project and receive seismic signals at an angle with respect to both a vertical plane and a horizontal plane.  
      Seismic exploration is generally significantly less costly than exploratory drilling for entrapped hydrocarbons. The improved data, information, and understanding regarding the potential presence and size of entrapped hydrocarbons in a given land formation obtained through directionally-variable seismic exploration in accordance with the present invention, therefore, will be highly beneficial to the field of hydrocarbon extraction. Specifically, the investments of time and money in actually drilling and extracting hydrocarbons will be more predictable in terms of the hydrocarbon yield and the associated costs to obtain.  
      Accordingly, once a trap is detected in a mountain or other land formation via the directionally-variable seismic exploration system of the present invention, the extraction method or system of the present invention may be used to extract the hydrocarbons from the detected trap or traps. The extraction system may provide a generally horizontal or upwardly inclined passage that starts at a location at the side of the mountain that is at or near the bottom of or below the detected trap, whereby the passage may intersect the trap to extract the hydrocarbons. Optionally, an upward passage may be formed or established at an end of the generally horizontal or inclined passage and at a location generally beneath the detected trap, whereby the upwardly inclined or generally vertical passage intersects the trap to drain the hydrocarbons from the trap via the generally L-shaped passage. The L-shaped passage may be formed via any suitable or known drilling means, such as described above.  
      Therefore, the present invention provides a directionally-variable seismic exploration system that provides enhanced detection of hydrocarbon traps within mountains or hills or the like. The present invention also provides a method of extracting the hydrocarbons from the detected trap or trap that provides enhanced access to the trap and enhanced removal of the hydrocarbons from the trap. The present invention thus provides a method of detecting and extracting hydrocarbons from land formations for which conventional detection and extraction systems are not highly suited. The extraction method provides enhanced and controlled extraction via gravity and/or downward flow of the hydrocarbons from the trap to a piping system.  
      Changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the present invention, which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the doctrine of equivalents.