Multi-Z polyline to single-Z horizons conversion

Method and system for 3-D imaging of subterranean geologic structures based on seismic data interpretations involves converting multi-Z polylines into single-Z line segments. The single-Z line segments have slopes that are either positive or negative and do not change signs. As a result, no point along the line segment has more than one value in Z. The single-Z line segments may then be grouped or assembled into lattices that may then be used to form single-z horizons. Such a method and system arrangement provide a far more efficient and less processing intensive way to render 3-D images of the geologic structures compared to existing solutions.

FIELD OF THE INVENTION

The exemplary embodiments disclosed herein relate generally to techniques for 3-D imaging and modeling of subterranean geologic structures using seismic data acquired from seismic reflection surveys taken of the subterranean formations, and particularly to a computer-implemented method, system, and computer program product for converting multi-Z polylines into single-Z line segments that may then be used to generate single-Z horizons or height fields.

BACKGROUND OF THE INVENTION

Seismic reflection surveys can reveal many structural details about a subterranean formation, including the location of subterranean faults, mineral deposits, and the like. It is desirable to accurately image and model the location and extent of these geologic structures owing to their importance in a number of commercial applications. For example, in hydrocarbon exploration, it is important to accurately model salt bodies and similar structures because such salt bodies are known to trap significant amounts of oil and gas in the formation underneath.

A common and widely used method of generating 3-D images of a salt body from seismic reflection surveys is to define the salt boundaries using horizons or height fields. Typically, an upward-facing or top horizon and a downward-facing or bottom horizon are defined for the salt body, then the salt structure between the top and bottom horizons is filled in by performing a flood fill. The data representing the horizons is usually stored and processed by imaging software using a 2-D array or grid where the elements in the grid represent points on the surface of the salt body in the horizontal direction (i.e., X and Y axes), and the value contained in each element indicates the depth (i.e., Z axis) of the salt boundary at that point.

However, constructing an accurate and realistic model of a salt body is inherently difficult because the nature of salt makes the seismic data noisy and poorly defined. In most cases, geologists and geophysicists must interpret the volumes of seismic data using their geological knowledge and experience to manually define the edge of the salt body as it is intersected by an individual vertical plane (section) and horizontal plane (slice). These seismic interpretations typically contain data points that were deemed by the geologists and geophysicists as most indicative of the boundary of the salt body. The data points are then input into imaging software, which connects the points together to form a set of polylines that outline the contour of the salt body. The imaging software then fills in the area between the polylines using the 2-D array or grid to render a 3-D image of the salt body.

Because salt bodies are closed structures, the polylines almost always encircle the salt body and are therefore almost always closed-ended. This means virtually every element in the 2-D array or grid for the image of a salt body will have at least two values in Z, with some elements having as many as four or more Z values, depending on the shape of the salt body. These multi-Z polylines are extremely computationally intensive and require a significant amount of processing power, making it difficult and time-consuming for the imaging software to render the salt body image or model.

A need therefore exists for improved techniques for 3-D imaging and modeling of subterranean geologic structures, and particularly for an efficient and less processing intensive way to render 3-D images of the geologic structures.

DETAILED DESCRIPTION OF THE DISCLOSED EMBODIMENTS

As an initial matter, it will be appreciated that the development of an actual, real commercial application incorporating aspects of the exemplary disclosed embodiments will require many implementation specific decisions to achieve the developer's ultimate goal for the commercial embodiment. Such implementation specific decisions may include, and likely are not limited to, compliance with system related, business related, government related and other constraints, which may vary by specific implementation, location and from time to time. While a developer's efforts might be complex and time consuming in an absolute sense, such efforts would nevertheless be a routine undertaking for those of skill in this art having the benefit of this disclosure.

It should also be understood that the embodiments disclosed and taught herein are susceptible to numerous and various modifications and alternative forms. Thus, the use of a singular term, such as, but not limited to, “a” and the like, is not intended as limiting of the number of items. Similarly, any relational terms, such as, but not limited to, “top,” “bottom,” “left,” “right,” “upper,” “lower,” “down,” “up,” “side,” and the like, used in the written description are for clarity in specific reference to the drawings and are not intended to limit the scope of the invention.

The exemplary disclosed embodiments relate to a computer-implemented method, system, and computer program product for 3-D imaging and modeling of subterranean geologic structures using seismic data. The embodiments involve converting multi-Z polylines into single-Z segments that may then be used to generate single-Z horizons or height fields for the geologic structures. It should be noted that although the following description and the figures focus on imaging salt bodies, the principles and teachings disclosed herein may also be applied to imaging other types of geologic structures by those having ordinary skill in the art.

Turning now toFIG. 1, an example of multi-Z polylines for a subterranean salt body is shown that are produced from data points or sample points manually selected by geologists and geophysicists. It is of course possible for the multi-Z polylines to be produced using automatically selected sample points without departing from the scope of the disclosed embodiments, as the particular way in which the sample points are selected is not critical to the practice of embodiments. Only two multi-Z polylines100and102are shown here for clarity and economy of the description, whereas a typical 3-D salt body image may include several dozen multi-Z polylines or more.

As can be seen, one multi-Z polyline100lies in an inline plane104while the other multi-Z polyline102lies in an xline plane106. The inline plane104and the xline plane106are orthogonal to one another and intersect each other along the dashed line indicated at108. Depth is indicated by the Z indicator. Along each polyline100and102are a plurality of small crosses resembling x's, one of which is indicated at110, that represent data points or sample points manually selected by the geologists and geophysicists. The two polylines100and102intersect each other at the two circled intersection points112and114along the dashed line108. In accordance with the exemplary disclosed embodiments, such multi-Z polylines100and102may be converted to their single-Z line segments as described herein in order to make rendering of the 3-D salt body image more efficient and less processor-intensive.

An example of a 3-D imaging system that can reduce multi-Z polylines to their single-Z line segments according to the exemplary disclosed embodiments is depicted generally inFIG. 2at200. As seen inFIG. 2, the exemplary 3-D imaging system200may be a conventional workstation, desktop, or laptop computer, or it may be a custom computing system developed for a particular application. In a typical arrangement, the system200includes a bus202or other communication pathway for transferring information within the 3-D imaging system200, and a CPU204coupled with the bus202for processing the information. The 3-D imaging system200may also include a main memory206, such as a random access memory (RAM) or other dynamic storage device coupled to the bus202for storing computer-readable instructions to be executed by the CPU204. The main memory206may also be used for storing temporary variables or other intermediate information during execution of the instructions to be executed by the CPU204.

The 3-D imaging system200may further include a read-only memory (ROM)208or other static storage device coupled to the bus202for storing static information and instructions for the CPU204. A computer-readable storage device210, such as a nonvolatile memory (e.g., Flash memory) drive or magnetic disk, may be coupled to the bus202for storing information and instructions for the CPU204. The CPU204may also be coupled via the bus202to a display212for displaying information to a user. One or more input devices214, including alphanumeric and other keyboards, mouse, trackball, cursor direction keys, and so forth, may be coupled to the bus202for communicating information and command selections to the CPU204. A network or communications interface216may be provided for allowing the 3-D imaging system200to receive or input data and otherwise communicate with an external device, system, or network.

The term “computer-readable instructions” as used above refers to any instructions that may be performed by the CPU204and/or other components. Similarly, the term “computer-readable medium” refers to any storage medium that may be used to store the computer-readable instructions. Such a medium may take many forms, including, but not limited to, non-volatile media, volatile media, and transmission media. Non-volatile media may include, for example, optical or magnetic disks, such as the storage device210. Volatile media may include dynamic memory, such as main memory206. Transmission media may include coaxial cables, copper wire and fiber optics, including wires of the bus202. Transmission itself may take the form of electromagnetic, acoustic or light waves, such as those generated during radio frequency (RF) and infrared (IR) data communications. Common forms of computer-readable media may include, for example, magnetic medium, optical medium, memory chip, and any other medium from which a computer can read.

A 3-D imaging application218, or rather the computer-readable instructions therefor, may also reside on or be downloaded to the storage device210. In general, the 3-D imaging application218is a computer program that can receive or input a plurality of data points reflecting seismic interpretations and render a 3-D image of a geologic structure, such as a salt body, based on those data points. Examples of commercially available 3-D imaging applications may include DecisionSpace® Geophysics from Landmark Graphics Corporation. The 3-D imaging application218may be executed by the CPU204and/or other components of the 3-D imaging system200to generate a model or image of the geologic structure. Such a 3-D imaging application218may be written in any suitable computer programming language known to those having ordinary skill in the art using any suitable software development environment known to those having ordinary skill in the art. Examples of suitable programming languages may include C, C++, C#, FORTRAN, MATLAB (from The MathWorks, Inc.), and LabVIEW (from National Instruments, Inc.), and the like. Examples of suitable software development environments include Visual Studio from Microsoft Corporation, and the like.

In accordance with the exemplary disclosed embodiments, the 3-D imaging application218may include among its features and capabilities a single-Z conversion module220. As the name suggests, the single-Z conversion module220is capable of receiving or inputting the seismic interpretations for a geologic structure and converting that data, which would otherwise be processed as multi-Z polylines, into single-Z line segments. The single-Z segments may then be used to compose single-Z horizons or height fields for the geologic structure. This allows the 3-D imaging application218to draw or render the geologic structure in a manner that is more efficient and requires much less processing power.

FIG. 3illustrates the single-Z conversion module220in more detail according to the embodiments disclosed herein. As can be seen, the single-Z conversion module220is composed of several functional components that, in some embodiments, may be software components, hardware components, or a combination of software and hardware components. These functional components may include a single-Z line segment identification sub-module300that is capable of analyzing the seismic interpretations for a geologic structure and identifying single-Z line segments from the interpretations. The functional components may also include a lattice generation sub-module302that operates to combine the single-Z line segments identified by the single-Z line segment identification sub-module300into individual groups or lattices of related segments. As well, the functional components may include a lattice rationalization sub-module304that functions to rationalize or break up each lattice as needed to ensure that no lattice folds back upon itself or overlaps itself.

General operation of the single-Z conversion module220, and the sub-modules300-304therein, is depicted inFIG. 4via a flow chart400. Although the flow chart400shows a number of discrete blocks, it should be understood that any block may be divided into two more constituent blocks, and that two or more blocks may be combined to form a single block, without departing from the scope of the exemplary disclosed embodiments. Also, although the various blocks are arranged in a particular sequence inFIG. 4, it should be understood that one or more of the blocks may be performed outside the sequence shown, or omitted altogether in some cases, without departing from the scope of the exemplary disclosed embodiments.

As can be seen inFIG. 4, in general, the single-Z conversion module220begins by receiving a multi-Z polyline reflecting a set of seismic interpretations at block402. At block404, the single-Z conversion module220breaks, divides, or otherwise reduces the multi-Z polyline into a plurality of contiguous single-Z line segments. Specifically, the single-Z conversion module220identifies sections or segments along the multi-Z polyline such that no point along an individual segment has more than one value in Z. This identification process continues until the entire multi-Z polyline has been converted to single-Z line segments. The single-Z conversion module220also assigns every single-Z line segments a unique identifier that allows it to be referenced as needed. The unique identifiers for the single-Z line segments may be any suitable identifier, such as an integer value, a numeric or alphanumeric sequence reflecting the relationship between the single-Z line segments and the multi-Z polyline, and the like.

Once the multi-Z polyline has been reduced to single-Z line segments, the single-Z conversion module220determines at block406whether there are additional multi-Z polylines that need to be converted. If the determination is yes, then the above process is repeated for the additional multi-Z polylines. If the determination is no, then the single-Z conversion module220groups or otherwise assembles the single-Z line segments into one or more lattices at block408, as explained in more detail herein. At block410, the lattices are rationalized or broken up as needed to ensure that no lattice folds back upon itself or overlaps itself. Thereafter, the rationalized lattices are gridded at block412and used to form compartments at block414in a manner well known to those having ordinary skill in the art.

FIG. 5shows an exemplary flowchart500of the steps that the single-Z conversion module220, and specifically the single-Z segment identification sub-module300therein, may use for the single-Z line segment identification block404(seeFIG. 4). In general, the identification of single-Z line segments begins with receiving a multi-Z polyline at block502. At block504, the slope or average slope of a line segment along the multi-Z polyline between a given sample point N−1 and the next sample point N is determined, and a comparison is made between that slope and the slope or average slope of a line segment between sample point N and sample point N+1. A determination is made at block506whether the comparison of the slope or average slope of the two line segments resulted in a sign change from positive to negative or vice versa, which would indicate the multi-Z polyline is starting to bend back around. If the determination at block506is yes, then a new single-Z line segment is identified at block508starting from sample point N. If the determination at block506is no, then the line segment starting from sample point N is simply added to the existing contiguous line segment and no new single-Z line segment is identified. This process ensures no line segment has a slope that changes sign from positive to negative or vice versa, and therefore no point along the line segment has more than one value in Z. Thereafter, at block510, a determination is made as to whether there are additional sample points for which a slope comparison is needed. The above process then either continues or terminates based on the outcome of this determination.

In addition to identifying new single-Z line segments, the single-Z conversion module220may also use the slope change comparisons of block508to identify whether the single-Z line segments belong in the top or bottom horizon. In some embodiments, the single-Z conversion module220may perform the top or bottom horizon determination by traversing the multi-Z polyline in a clockwise direction according to the orientation of the polyline. Then, a sign change in the slope between successive line segments not only indicates the start of a new single-Z line segment, but also indicates the horizon for the new single-Z line segment. Specifically, a sign change from positive to negative indicates the new single-Z line segment belongs in the bottom horizon, whereas a sign change from negative to positive indicates the new single-Z line segment belongs in the top horizon.

FIGS. 6A-6Dillustrate examples of multi-Z polylines and their corresponding single-Z line segments that may be identified by the single-Z conversion module220according to the exemplary embodiments disclosed herein. Referring first toFIGS. 6A and 6B, inline planes labeled A and B are shown, respectively, that are parallel to one another and to the surface of the page.FIGS. 6C and 6Dshow xline planes labeled C and D, respectively, that are parallel to one another and to the surface of the page, but orthogonal to the inline planes A and B. The relative orientations may be seen inFIGS. 6A and 6Bwhere the xline planes C and D are designated with short-dash lines labeled C and D, respectively, and likewise inFIGS. 6C and 6Dwhere the inline planes A and B are designated with short-dash lines labeled A and B, respectively.

Referring still toFIGS. 6A-6D, solid lines within the various planes represent multi-Z polylines similar to those commonly rendered in a typical workflow based on seismic interpretations. The long dash lines and the dash-dot lines represent single-Z line segments corresponding to the multi-Z polylines identified according to the exemplary disclosed embodiments. In particular, the long dash lines represent single-Z line segments that reside in one of the height fields, for example, the top horizon, whereas the dash-dot lines represent single-Z line segments that reside in the other height field, for example, the bottom horizon. Here, the small crosses resembling x's represent points where the various inline and xline multi-Z polylines intersect one another.

Turning now toFIG. 6A, a portion of an inline multi-Z polyline is shown, as represented by the solid line600. This portion of the inline multi-Z polyline600may be reduced by the single-Z conversion module220in the manner described above to a top horizon single-Z line segment21and a bottom horizon single-Z line segment42. At least four xline multi-Z polylines intersect the inline multi-Z polyline600at intersection points0,1,2, and3. These four xline multi-Z polylines may also be reduced in the manner described above to a top horizon single-Z line segment27that crosses intersection point0, a bottom horizon single-Z line segment48that crosses intersection point1, another top horizon single-Z line segment31that crosses intersection point2, and another bottom horizon single-Z line segment52that crosses intersection point3.

The intersection points0and1fromFIG. 6Amay also be seen inFIG. 6C, along with the xline single-Z line segments27and48extending through these intersection points. Looking atFIG. 6C, it can be seen that the single-Z line segments27and48fromFIG. 6Aactually correspond to an xline multi-Z polyline604. To avoid clutter, this xline multi-Z polyline604is not specifically depicted inFIG. 6A, which instead shows the corresponding single-Z line segments27and48for clarity.FIG. 6Calso shows the inline single-Z line segments21and42fromFIG. 6Aextending through the intersection points0and1.

The other intersection points fromFIG. 6A, points2and3, may also be seen in FIG. D, along with the xline single-Z line segments31and52extending through them. These single-Z line segments31and52correspond to xline multi-Z polyline608. Again, to avoid clutter, this xline multi-Z polyline608is not specifically depicted inFIG. 6A, which shows the single-Z line segments31and52instead for clarity.

The remaining inline and xline multi-Z polylines inFIGS. 6A-6D, their corresponding inline and xline single-Z line segments, as well as the various intersection points, may be cross referenced to one another in the same fashion as above. For example,FIG. 6Bshows a portion of an inline multi-Z polyline602, two top horizon single-Z line segments23and25resulting therefrom, two bottom horizon single-Z line segments44and46resulting therefrom, and six intersection points4,5,6,7,8, and9that are intersected, respectively, by six single-Z line segments27,48,29,50,31, and52. All of these intersection points and the inline single-Z line segments extending through them may also be seen and cross referenced inFIGS. 6C and 6D.

Similarly,FIG. 6Cshows an xline multi-Z polyline604, a top horizon single-Z line segment27resulting therefrom, a bottom horizon single-Z line segment48resulting therefrom, and four intersection points0,1,4, and5that are intersected, respectively, by four inline single-Z line segments21,42,23, and46. All of these intersection points and the single-Z line segments extending through them may also be seen and cross referenced inFIGS. 6A and 6B.

Finally,FIG. 6Dshows two xline multi-Z polylines606and608, two xline single-Z line segments29and50resulting from the first polyline606, and two xline single-Z line segments31and52resulting from the second polyline608. As well, there are two intersection points6and7along the first polyline606that are intersected, respectively, by the inline single-Z line segments23and44, and four intersection points2,3,8, and9along the second polyline608that are intersected, respectively, by the inline single-Z line segments21,42,25, and46. All of these intersection points and the single-Z line segments extending through them may also be seen and cross referenced inFIGS. 6A and 6B.

A simplistic example to illustrate the single-Z conversion concepts discussed above is provided below in Tables 1, 2 and 3. In this example, the tables are rough facsimiles of a portion of the 2-D arrays or grids of a given multi-Z polyline for a geologic structure. Referring to Table 1, there are two values in Z at point X=1 and Y=3 of the polyline, namely, Z=4 and 24. Tables 2 and 3 are the top and bottom horizon single-Z line segments, respectively, corresponding to the polyline after it has been converted according to the exemplary embodiments disclosed herein. As can be seen in Tables 2 and 3, there is now only one value in Z for each line segment at point X=1 and Y=3.

Once the single-Z line segments have been identified for the various multi-Z polylines, the single-Z conversion module220, and specifically the lattice generation sub-module302therein, may assemble or otherwise group the line segments together to form lattices, as depicted in block408(seeFIG. 4). An example of creating a lattice is shown inFIG. 7in the form of a flowchart700. In general, lattice creation starts with receiving or inputting a single-Z line segment for a given multi-Z polyline at block702. Next, based on whether the received single-Z line segment is a top horizon line segment (long dash) or a bottom horizon line segment (dash-dot), additional top or additional bottom horizon line segments may be added to the lattice. In particular, the received single-Z line segment is traced or followed out to its intersection points at block704, and any top or bottom horizon single-Z line segments crossing through or connected to the intersection points are added accordingly at block706. At block708, the newly added single-Z line segments are traced or followed out to their respective intersection points. A determination is then made at block710whether there are any additional top or additional bottom horizon single-Z line segments that need to be added to the lattice. If the determination is yes, then the previous adding steps at blocks706and708are repeated, and the process continues in a recursive manner until all intersection points branching off from the initial single-Z line segment have been walked, and all top or bottom single-Z line segments connected to those intersection points have been added to the lattice accordingly.

If the determination at block710is no, then a determination is made at block712whether any unused single-Z line segments, that is, any single-Z line segments that have not been added to a lattice, remain. If the determination is yes, then the process returns to block702and a new lattice is started from the unused single-Z line segment. If the determination is no, then the process is terminated.

FIGS. 8A-8Cillustrate examples of single-Z line segments grouped together by the single-Z conversion module220to form lattices according to the exemplary embodiments discussed above. In the example ofFIG. 8A, a top horizon lattice800is shown having five of the intersection points0,2,4,6, and8initially discussed with respect toFIGS. 6A-6D. These intersection points are connected to each other by the single-Z line segments21,23,25,27,29, and31, to form the lattice800as shown. In a similar manner,FIG. 8Bshows a lattice802having four intersection points1,3,5, and9that are connected to one another by the bottom horizon single-Z line segments42,46,48, and52.FIG. 8Cshows a lattice804having one intersection point7and two bottom horizon single-Z line segments44and50.

Due to the way the single-Z conversion module220constructs the lattices in some embodiments, it may be possible for a lattice to fold back over itself and overlap itself. One option for preventing this overlapping is to rationalize or break up the lattices so that no lattice contains single-Z line segments that lie in the same inline or xline plane, as discussed with respect to block410(seeFIG. 4).FIG. 9shows an example of the single-Z conversion module220, and specifically the lattice rationalization sub-module304therein, rationalizing a lattice in accordance with the exemplary disclosed embodiments. In general, referring to the flowchart900inFIG. 9rationalization begins with receiving an inline or xline lattice at block902. At block904, a determination is made whether any of the single-Z line segments in the lattice share the same plane. If the determination is yes, then at block906, the lattice is broken at whichever single-Z line segment is: 1) nearest to the single-Z line segments sharing a plane, and 2) in a plane parallel to the shared plane.

If the determination at block904is no, then a determination is made at block908whether any additional lattices need to be rationalized. If yes, then the process returns to block902for additional lattice rationalization. If no, then the process terminates.

Turning back toFIG. 8A, the top horizon lattice800shown here is an example of a lattice that has been rationalized by the single-Z conversion module220. As depicted, the top horizon lattice800includes two single-Z line segments23and25that share the same plane, namely, inline plane B (seeFIG. 6B). In accordance with the exemplary disclosed embodiments, the single-Z conversion module220has determined the single-Z line segment21to be the nearest line segment that also resides in a plane parallel to the single-Z line segments23and25(seeFIG. 6A). The single-Z line segments27,29, and31, on the other hand, reside in different xline planes C and D (seeFIGS. 6C and 6D). Therefore, the single-Z conversion module220has broken the top horizon lattice800at the single-Z line segment21such that the single-Z line segments23and25no longer have a continuous, unbroken path between them via the single-Z line segment21. This may be achieved in the example ofFIG. 8Aby breaking the single-Z line segment21between the intersection points0and2.

In contrast, the single-Z conversion module220does not need to break up the bottom horizon lattice802inFIG. 8Bbecause none of its single-Z line segments42,46,48, or52share the same plane. This may be verified by reference toFIGS. 6A-6D, which shows each of the single-Z line segments42,46,48, and52residing in different planes from one another. Likewise, the bottom horizon lattice804inFIG. 8Calso does not need to be broken up, as none of its single-Z line segments44and50share the same plane (seeFIGS. 6B and 6D).

Thus, as set forth above, the embodiments disclosed herein may be implemented in a number of ways. In general, in one aspect, the exemplary disclosed embodiments relate to a computer-based imaging system for imaging a geologic structure in a subterranean formation. The system comprises, among other things, a central processing unit mounted within the computer-based imaging system, a display electrically connected to the central processing unit and displaying a three-dimensional (3-D) image of the geologic structure, and a data input unit electrically connected to the central processing unit, the data input unit receiving seismic interpretations for the geologic structure, the seismic interpretations comprising interpretations of data acquired from a seismic reflection survey taken of the subterranean formation. The system further comprises a storage device electrically connected to the central processing unit and storing an imaging application executable by the central processing unit to render the seismic interpretations as multi-Z polylines, each multi-Z polyline being composed of a series of sample points defining a different contour of the geologic structure within a given plane, and each multi-Z polyline having a plurality of intersection points where the multi-Z polyline intersects other multi-Z polylines. The storage device further stores a single-Z conversion module executable by the central processing unit to convert the multi-Z polylines into single-Z line segments such that each multi-Z polyline is converted into a set of contiguous single-Z line segments, and each single-Z line segment has only one value in Z at any point along the single-Z line segment.

In general, in another aspect, the exemplary disclosed embodiments relate to a computer-based method of imaging a geologic structure in a subterranean formation. The method comprises, among other steps, receiving seismic interpretations for the geologic structure through a data input unit, the seismic interpretations comprising interpretations of data acquired from a seismic reflection survey taken of the subterranean formation. The method further comprises rendering the seismic interpretations as multi-Z polylines using a central processing unit, each multi-Z polyline being composed of a series of sample points defining a different contour of the geologic structure within a given plane, and each polyline having a plurality of intersection points where the multi-Z polyline intersects other multi-Z polylines. The multi-Z polylines are converted into single-Z line segments using the central processing unit such that each multi-Z polyline is converted into a set of contiguous single-Z line segments, and each single-Z line segment has only one value in Z at any point along the single-Z line segment.

In general, in yet another aspect, the exemplary disclosed embodiments relate to a computer-readable medium storing computer-readable instructions for causing a computer to image a geologic structure in a subterranean formation. The computer-readable instructions comprise instructions for causing the computer to, among other things, receive seismic interpretations for the geologic structure, the seismic interpretations comprising interpretations of data acquired from a seismic reflection survey taken of the subterranean formation the computer readable instructions further comprise instructions for causing the computer to render the seismic interpretations as multi-Z polylines, each multi-Z polyline being composed of a series of sample points defining a different contour of the geologic structure within a given plane, and each polyline having a plurality of intersection points where the multi-Z polyline intersects other multi-Z polylines. The multi-Z polylines are converted into single-Z line segments such that each multi-Z polyline is converted into a set of contiguous single-Z line segments, and each single-Z line segment has only one value in Z at any point along the single-Z line segment.

While particular aspects, implementations, and applications of the present disclosure have been illustrated and described, it is to be understood that the present disclosure is not limited to the precise construction and compositions disclosed herein and that various modifications, changes, and variations may be apparent from the foregoing descriptions without departing from the spirit and scope of the exemplary disclosed embodiments as defined in the appended claims.