Patent Publication Number: US-2017357017-A1

Title: Systems and methods for improved coupling of geophysical sensors, where the shaft is open at the foot and couples to the sensor base plate at the head

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit under 35 U.S.C. §119(e) of U.S. Provisional Application Ser. No. 62/103,163 filed on Jan. 14, 2015, which is incorporated by reference in its entirety for all purposes. 
    
    
     TECHNICAL FIELD 
     The present disclosure relates generally to seismic exploration tools and processes and, more particularly, to a system and method for coupling geophysical sensors. 
     BACKGROUND 
     In the oil and gas industry, geophysical survey techniques are commonly used to aid in the search for and evaluation of subterranean hydrocarbon or other mineral deposits. Generally, a seismic energy source, or “source,” generates a seismic signal that propagates into the earth and is partially reflected by subsurface seismic interfaces between underground formations having different acoustic impedances. Geophysical or seismic detectors, or “sensors,” located at or near the surface of the earth, in a body of water, or at known depths in boreholes, record the reflections and the resulting seismic data can be processed to yield information relating to the location and physical properties of the subsurface formations. Seismic data acquisition and processing generates a profile, or image, of the geophysical structure under the earth&#39;s surface. While this profile does not provide an accurate location for oil and gas reservoirs, it suggests, to those trained in the field, the presence or absence of them. 
     The seismic signal is emitted in the form of a wave that is reflected off interfaces between geological layers. When the wave encounters an interface between different media in the earth&#39;s subsurface a portion of the wave is reflected back to the earth&#39;s surface while the remainder of the wave is refracted through the interface. The reflected waves are received by an array of geophones, or geophysical sensors, located at the earth&#39;s surface, which convert the displacement of the ground resulting from the propagation of the waves into an electrical signal recorded by means of recording equipment. 
     Measured at the surface, received waves are minuscule variations in the displacement of the ground in which sensors are placed. Due to the nature of the received waves, it is paramount that that the motion of the sensors match that of the ground. Otherwise the recorded signal is not representative of its subsurface source. Geophysical sensors are usually installed using a spike that penetrates the earth&#39;s surface to provide a mechanical coupling and to enable the shear force acting on the spike to hold the sensor firmly in place. However, spikes can be considered a safety hazard, difficult to mechanize the deployment of, and tend to make dealing with large quantities of pre-connected line segments difficult. 
     In certain operating environments, the native soil is either unconsolidated or relatively inelastic. Both of these features make it difficult to “couple” the sensors. In unconsolidated soil the particles are loosely bound to one another and prone to movement. The result is the absorption of the incident signal by the translated motion of the soil particles. In this situation, operators often attempt to “dig down” in search of a more solid substrate in which to mechanically attach the sensor. Inelastic soils appear to be hard, or exhibit good compressive strength, but when disturbed, even by the diameter of the sensor itself, inelastic soils become brittle. Inelastic soil is difficult to displace and the act of digging to get the sensor below the adjacent surface can cause the ground to become unconsolidated. Accordingly, the need for a mass deployment of sensors coupled with difficult terrain leaves little option to use a traditional ground spike. 
     Some sensors include an integrated screw thread to assist in installation. But disturbance of the terrain due to threaded devices can be detrimental to the quality of seismic coupling between the sensor and the surrounding medium. Also, because sensors are electrical devices, the attached electrical cable makes them difficult to rotate, especially when the installation process is to be mechanized. 
     Additionally, some sensors are installed using separate screw devices. While the act of placing a screw into the terrain seems rather trivial; there is difficulty in ensuring that the sensor can be well coupled to the terrain after the fact. Mechanically this means that the tolerances must be tight and that some form of clamping force is provided. In a typical seismic environment, these tolerances are difficult to manage or keep clean and clamping mechanisms tend to be tedious and a burden on field workers. In addition, the need for mechanization requires as few precision functions as possible. 
     Other installation options include placing a screw device through some opening in the sensor body where the hold down force of the screw pins the sensor to the ground (as though the sensor were a washer). Again, this type of installation entails a rather precise operation where the screw needs to be lined up with the sensors hole and the amount of drive force regulated to prevent damaging the sensor. Such a process is also difficult to mechanize. 
     SUMMARY 
     In some embodiments, a method for deploying a geophysical sensor includes determining conditions at an installation location, and selecting a sensor assembly. The sensor assembly includes a threaded device having a shaft with a foot and a head. The threaded device has a cavity that is open at the foot and extends inside the shaft from the foot to the head. The sensor assembly further includes a baseplate configured to couple to the threaded device. The method also includes preparing the installation location for installation of the selected sensor assembly and installing the selected sensor assembly at the installation location. 
     In another embodiment, a geophysical sensor assembly includes a threaded device having a shaft with a foot and a head. The threaded device has a cavity that is open at the foot and extends inside the shaft from the foot to the head. The geophysical sensor assembly also includes a baseplate configured to couple to the threaded device. 
     In another embodiment, a method for deploying a geophysical sensor includes determining conditions at an installation location, and selecting a sensor assembly. The sensor assembly includes a shaft with a foot and a head. The shaft has a cavity that is open at the foot and extends inside the shaft from the foot to the head. The head includes a sensor and an interface. The method also includes preparing the installation location for installation of the selected sensor assembly, and installing the selected sensor assembly at the installation location. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present disclosure and its features and advantages, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which like reference numbers indicate like features and wherein: 
         FIG. 1  illustrates an exemplary configuration of a geophysical sensor assembly that is disassembled in accordance with some embodiments of the present disclosure; 
         FIG. 2  illustrates an exemplary configuration of a geophysical sensor assembly that is assembled in accordance with some embodiments of the present disclosure; 
         FIG. 3  illustrates an exemplary cross-section of a geophysical sensor assembly in accordance with some embodiments of the present disclosure; 
         FIG. 4  illustrates an example geophysical sensor insertion at an installation location in accordance with some embodiments of the present disclosure; 
         FIG. 5  illustrates an example excavation of a level surface in accordance with some embodiments of the present disclosure; 
         FIG. 6  illustrates an exemplary multicomponent sensor assembly in accordance with some embodiments of the present disclosure; 
         FIG. 7  illustrates an example of an active sensor assembly in accordance with some embodiments of the present disclosure; 
         FIG. 8  illustrates an example of a collar used with the active sensor assembly of  FIG. 7  in accordance with some embodiments of the present disclosure; 
         FIG. 9  illustrates a flow chart of example method  900  for installing geophysical sensors for seismic exploration in accordance with some embodiments of the present disclosure; and 
         FIG. 10  illustrates an elevation view of an example seismic exploration system configured to produce images of the earth&#39;s subsurface geological structure in accordance with some embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure is directed to systems and methods for improved coupling of geophysical sensors. As discussed previously, areas of unconsolidated or relatively inelastic terrain makes installation of sensors difficult for multiple reasons. Further, insufficient mechanical coupling between the sensor and the earth&#39;s surface decreases the effectiveness or accuracy of the data collected at the geophysical sensor. In some embodiments, installation of sensors is accomplished by the use of a geophysical sensor assembly that includes a threaded device and a baseplate that can be easily coupled to the threaded device. The sensor may be affixed to the baseplate prior to coupling to the threaded device. The baseplate may be configured or oriented for a particular sensor, or may be configured or oriented to couple to multiple sizes or types of sensors. The baseplate may also be configured to attach to one or multiple configurations of threaded devices. The interface between the baseplate and the threaded device may allow adjustment of the orientation of the sensor. The particular threaded device and baseplate utilized is selected by an operator based on the terrain where the geophysical sensor is to be installed. In some surveys, the terrain across an exploration area varies. As such, the operator may select different configurations of threaded devices and baseplates for installation of geophysical sensors in different locations based on terrain variations. 
     In some embodiments, an active sensor assembly may be utilized that integrates the mechanism for coupling with the terrain and the sensor. The geophysical sensor and associated components are integrated into the top, or “head,” of the active sensor assembly. Each active sensor assembly may then be electronically coupled to other sensors through the use of a collar and an active string or cable. The cable may provide power and data communication to each of the active threaded devices. Thus, in some embodiments, the present disclosure assists in installation of geophysical sensors to improve mechanical coupling of the sensor with the earth&#39;s surface. Improved mechanical coupling may result in more accurate readings and data. Further, in some embodiments, the present disclosure provides installation methods for the geophysical sensors that may decrease risks to health and safety. 
     As used herein, a hyphenated form of a reference numeral refers to a specific instance of an element and the un-hyphenated form of the reference numeral refers to the collective or generic element. Thus, for example, widget “ 72 - 1 ” refers to an instance of a widget class, which may be referred to collectively as widgets “ 72 ” and any one of which may be referred to generically as a widget “ 72 ”. 
       FIG. 1  illustrates an exemplary configuration of a geophysical sensor assembly that is disassembled in accordance with some embodiments of the present disclosure. In some embodiments, sensor assembly  100  includes threaded device  102  and baseplate  104 . Threaded device  102  includes threads  106  to allow insertion into an installation location, such as the earth&#39;s surface. Threaded device  102  is inserted into the installation location using an insertion tool that is configured to exert the necessary force and torque to ensure that the threaded device  102  travels into the surface with minimum disturbance to the consolidation of the surrounding surface. For example, the force and torque may be applied to move threaded device  102  into the surface in a rotational step-wise manner that corresponds with threads  106  on threaded device  102 . The torque and force exerted by the insertion tool is based at least in part on the configuration of threads  106  and the terrain at the installation location. A drive shaft of the insertion tool is configured to mate with tool recess  108 . Although tool recess  108  is illustrated as hexagonal, tool recess  108  may be of any suitable configuration to mate with the drive shaft of the insertion tool. 
     In some embodiments, threads  106  are configured based on the terrain conditions of the installation location and based on minimum disruption of the terrain during insertion. The pitch of threads  106  are also configured to minimize disturbance of the installation location during vertical movement of the threaded device  102  into the surface. For example, if the terrain at the installation location is substantially unconsolidated, such as sandy soil, threads  106  may include wider paddles or helical ridges and may include a lower pitch. As another example, if the terrain is substantially inelastic, consolidated, or packed, threads  106  may include narrower helical ridges and a higher pitch. Following installation of threaded device  102  into the installation location, additional degrees of rotation may be applied by the insertion tool to ensure a positive downward force is exerted by the surrounding surface on threaded device  102 . 
     In some embodiments, coupling between threaded device  102  and baseplate  104  may be via magnetic coupling. As such, one or both of threaded device  102  and baseplate  104  is constructed of materials that facilitate magnetic coupling between top surface  110  of threaded device  102  and bottom surface  112  of baseplate  104 . For example, threaded device  102  or baseplate  104  may be constructed of any ferromagnetic material, such as metal, a hard plastic that includes magnetic material or particles, or any other suitable material that allows for magnetic coupling. In some embodiments, threaded device  102  may be constructed of a material without magnetic properties, such as hard plastic or aluminum. In some embodiments, threaded device  102  or baseplate  104  are constructed with a material of sufficient hardness or stiffness to minimize or eliminate any resonances at frequencies within the frequencies of the seismic band. Further, threaded device  102  is constructed of a material that withstands insertion at the installation location without substantial deformation. Additionally, threaded device  102  is constructed of a material that facilitates mechanical coupling to the terrain of the earth&#39;s surface at the installation location. In some embodiments, each of threaded device  102  or baseplate  104  may be constructed of two or more materials with one material having magnetic properties, for example, a thin ferromagnetic plate. 
     Magnets or magnetic material in threaded device  102  and baseplate  104  may assist in the insertion and removal of sensor assembly  100 . For example, magnetic material assists in retaining threaded device  102  on a drive shaft of the insertion tool as threaded device  102  is inserted at the installation location. As another example, during removal, the magnetic field generated by threaded device  102  and baseplate  104  may be sensed to locate sensor assembly  100  and also utilized to fasten sensor assembly  100  to an extraction tool. 
     Given the tolerance requirements of a simple mechanical fastening system and the installation environment, such as a harsh desert, magnetic coupling between threaded device  102  and baseplate  104  may be optimal due to no moving parts and blind assembly capabilities. 
     To facilitate magnetic coupling, in some embodiments, threaded device  102  may include one or more cavities  114 - 1  and  114 - 2  for housing one or more magnets. The magnets are construed of strong, rare earth magnets, other magnetic metals, ferrites, or alloys that exhibit ferromagnetic properties to provide the sufficient magnetic coupling force with baseplate  104 , or other component as appropriate. Although cavities  114 - 1  and  114 - 2  illustrate the installation of similarly sized magnets, any suitable number and size of magnets may be utilized in any suitable orientation or location with respect to the structure in which they are configured. For example, one larger cavity  114  and associated magnet may be utilized in place of cavities  114 - 1  and  114 - 2  and associated magnets to couple threaded device  102  and baseplate  104 . 
     In addition to providing the coupling force between threaded device  102  and baseplate  104 , the magnets, or magnetic elements, may also be used to ensure a specific alignment, vertical and horizontal, between threaded device  102  and baseplate  104 . In instances where the installation of threaded devices  102  is mechanized, both threaded device  102  and baseplate  104  may utilize the same type of magnetic element (but polar opposites) and threaded device  102  and baseplate  104  may be automatically aligned. 
     Although discussed with respect to magnetic coupling, in some embodiments, other coupling mechanisms between threaded device  102  and baseplate  104  are utilized. For example, baseplate  104  may be substantially affixed to threaded device  102  via screws, fasteners, welds, adhesive, or any other suitable fastening mechanism. The coupling force may be sufficient to maintain the mechanical integrity of the interfaces between the components of the geophysical sensor assembly. Mechanical integrity may refer to the need to minimize or eliminate any movement of components of the geophysical sensor assembly relative to each other that allow the components to become loose, rattle, or otherwise individually move. 
     In some embodiments, shaped interfaces to provide improved mechanical coupling at the interfaces between components of sensor assembly  100  are used in addition to the magnetic coupling. In some embodiments, threaded device  102  includes top surface  110  of head  124  having a convex shape that is substantially domed, conical, or hemi-spherical. The domed, conical, or hemi-spherical shape of top surface  110  assists in shedding sand or other debris and allow for adjustment of baseplate  104 . For example, if threaded device  102  is installed in the surface such that it is not oriented directly vertical, the domed, conical, or hemi-spherical shape of top surface  110  allows adjustment of baseplate  104  to compensate for the orientation of threaded device  102 , both vertically and azimuthally. As such, bottom surface  112  of baseplate  104  has a concave surface configured to couple with top surface  110  of threaded device  102 . Use of a domed, conical, or hemi-spherical shape for top surface  110  enables coupling of threaded device  102  and baseplate  104  without significant human interaction or precision assemblies. Further, although the interface between threaded device  102  and baseplate  104  is illustrated and described using a domed, conical, or hemi-spherical shape, the surface at the interface may be of any shape or structure that provides for coupling and may improve structural integrity of the interface. 
     As illustrated in  FIG. 1 , shaft  120  of threaded device  102  may be substantially cylindrically shaped and foot  122  of threaded device  102  may be substantially flat. In some embodiments, shaft  120  may be configured in any suitable shape, for example, shaft  120  may be tapered from head  124  to foot  122 . Additionally, foot  122  may be configured in any suitable shape. For example, foot  122  may have a convex shape or may include teeth, flanges, or spikes as suitable for the particular implementation. 
     In some embodiments, top surface  116  of baseplate  104  may include channel  118 . Channel  118  may be of any size or configuration to allow installation of a sensor. In some embodiments, top surface  116  of baseplate  104  may not include channel  118  and may be substantially flat. The configuration of top surface  116  is arranged per the specific implementation or specific sensor that is coupled to baseplate  104 . 
     Although discussed with reference to geophysical sensors, sensor assembly  100  may be used for insertion of any device employed to determine a property at the installation location. For example, sensor assembly  100  may be utilized with soil content measurement devices, sea level measurement devices, or any other suitable devices. Additionally, an operator selects a particular configuration of sensor assembly  100  based on the necessary mechanical coupling force, the orientation of the assembly with respect to the terrain at the installation location, the need to interchange or exchange the components for use at another location, characteristics of the terrain at the installation location, or any other suitable factor based on the specific implementation. 
     Embodiments of the present disclosure are suited for deployment in land surveys or ocean bottom surveys. In ocean bottom implementations, sensor assembly  100  may be encased in plastic or other substantially waterproof or water resistant material. 
       FIG. 2  illustrates an exemplary configuration of a geophysical sensor assembly that is assembled in accordance with some embodiments of the present disclosure. Sensor assembly  100  is shown with baseplate  104  coupled to the top of threaded device  102 . Using magnetic coupling, the present disclosure minimizes or eliminates the need for tools or special fixtures to accomplish modifications in the field. Further, the present disclosure maintains a low level of mechanical complexity based on the lack of moving parts. With respect to forces experienced by the geophysical sensor assembly, the use of magnetic coupling and shaped interfaces provides a single fastening point approximately in the center of the interfaces. A single fastening point reduces or eliminates any resultant asymmetrical forces that may result from an imbalance in forces related to having multiple fasteners. 
       FIG. 3  illustrates an exemplary cross-section of a geophysical sensor assembly in accordance with some embodiments of the present disclosure. Threaded device  102  includes cavity  302  extending substantially through the center of threaded device  102  from foot  122  to head  124 . Accordingly, at foot  122 , threaded device  102  is substantially open. Cavity  302  creates a hollow opening extending partially through threaded device  102 . Use of cavity  302  assists in ensuring that disturbance to the installation surface is minimized during insertion of threaded device  102 . During insertion of threaded device  102 , cavity  302  may be filled with soil or other material present at the installation location. The thickness of shaft  120  that encompasses cavity  302  is based on the force or torque required to insert sensor assembly  100  at the installation location. For example, the thickness of shaft  120  is sufficient such that threaded device  102  is able to withstand the force or torque required for insertion with insubstantial deformation. Moreover, threaded device  102  may be construction of biodegradable or environmentally neutral materials. 
     In some embodiments, opening  304  extends substantially through baseplate  104  to allow coupling to a sensor by means of a screw or rivet. Opening  304  may be countersunk on bottom surface  112  of baseplate  104  to allow for improved coupling between baseplate  104  and threaded device  102 . Opening  304  may be a threaded hole, partially threaded or may have a smooth surface based on the requirements of the specific implementation. 
       FIG. 4  illustrates an example geophysical sensor insertion at an installation location in accordance with some embodiments of the present disclosure. Insertion  400  includes sensor assembly  100  coupled with sensor  402 . In some embodiments, sensor assembly  100  and sensor  402  are installed directly into level surface  404 . In some embodiments, level surface  404  is excavated prior to installation. 
     For example,  FIG. 5  illustrates an example excavation of a level surface in accordance with some embodiments of the present disclosure. Rotating shovel  500  includes axis  502  and blade  504 . In operation, rotation shovel  500  is rotated in a direction shown by arrow  506 . Blade  504  may be tapered or may be of any other suitable configuration to create recess  406 . Rotating shovel  500  creates recess  406  in level surface  404 . 
     Returning to  FIG. 4 , recess  406  allows installation of sensor assembly  100  and sensor  402  below level surface  404 . Recessed installation of sensor  402  minimizes noise caused by wind or other environmental effects on signals received or recorded by sensor  402 . Additionally, after installation, the top surface of sensor  402  may be covered by dirt, sand, or other debris that was previously removed during excavation. For example, during excavation, cuttings from recess  406  are deposited on the outside perimeter of the hole. A vacuum system may be used to pick up the cuttings created during creation of recess  406 , and deposit the cuttings on and around sensor  402  after sensor assembly  100  and sensor  402  are installed. 
     In some embodiments, cables  408  are coupled and extend from sensor  402  to connect sensor  402  with other sensors or a computing system. Cables  408  may provide for power, data, and communication. In some embodiments, recess  402  is sized and configured such that cables  408  coupled to sensor  402  gently slope up and out. Although discussed with cables  408  coupling sensors  402 , any suitable method may be utilized for providing power, data, or communications between and among sensors  402 . For example, power may be supplied by a battery and communication may be supplied by an antenna or other wireless communication protocol. 
     Sensor  402  is any suitable device that measures or detects a property of the surface or subsurface. In some embodiments, sensor  402  is any type of instrument that is operable to transform seismic energy or vibrations into a voltage signal. For example, sensor  402  may be a vertical, horizontal, or multicomponent geophone, accelerometers, or optical fiber with wire or wireless data transmission, such as a three component (3C) geophone, a 3C accelerometer, or a 3C Digital Sensor Unit (DSU). Multiple sensors  402  may be utilized within an exploration area to provide data related to multiple locations and distances from seismic sources. Sensors  402  may be positioned in multiple configurations, such as linear, grid, array, or any other suitable configuration. 
     During installation, threaded device  102  is inserted at an installation location that may have been excavated to form a recess  406 . Threaded device  102  is inserted using an insertion tool that screws threaded device  102  into the installation location. The insertion tool exerts the necessary force and torque to ensure that threaded device  102  moves into the media at the installation location with as little disturbance of the consolidation of the surrounding media as possible. As such, the required force and torque are associated in such a way that threaded device  102  moves downward into the media with the same step as the threads  106  on threaded device  102 . Use of an insertion tool allows measurement of the torque and downward pressure (or force) required to insert threaded device  102 . The torque and force required may be recorded for each sensor installation location, and may be used to map very near surface conditions by establishing a correlation between the mechanical measurements and geophysical properties, such as, P-wave and S-wave velocity, absorption, or other suitable characteristics. 
     Multiple sensors  402  may be individually attached to baseplates  104  prior to coupling the baseplates  104  with threaded devices  102 . Then, each of baseplates  104  are coupled to threaded devices  102 . Installation of sensors  402  may include covering sensors  402  with soil, a sand bag, or other material or structure, to reduce or substantially prevent wind noise and improve mechanical coupling with the earth&#39;s surface. Soil may be gathered from nearby terrain or from the creation of recesses  406  for placement of sensors  402 . 
       FIG. 6  illustrates an exemplary multicomponent sensor assembly in accordance with some embodiments of the present disclosure. In multicomponent sensor assembly  600 , a sensor may be placed inside threaded device  602 . Including a sensor in threaded device  602  may reduce or minimize the vertical component of rotation of threaded device  602 . Rotation of the sensor can provoke an unwanted vertical component of the media movement if rotation is about any axis which is not at the center of the sensor. Placing the center of the sensor at the center of threaded device  602  may mitigate this problem (often called “rocking” by those skilled in the art). Portions or all of multicomponent sensor assembly  600  may be utilized in combination with portions of sensor assembly  100 , discussed with reference to  FIGS. 1 through 5 . 
     Assembly  600  may include threaded device  602 , receptacle  604 , and cover  606 . Threaded device  602  may include one cavity  608 - 1  for retaining a sensor. Receptacle  604  may include cavities  608 - 2  and  608 - 3  for retaining a sensor each. Each of cavities  608  is configured to be orthogonal to other cavities  608 . 
     Threaded device  602  includes threads  610  to allow insertion into an installation location, such as the earth&#39;s surface. Threaded device  602  may be inserted into the installation location using an insertion tool that is configured to exert the necessary force and torque to ensure that the threaded device  602  travels into the surface with minimum disturbance to the consolidation of the surrounding surface. For example, the force and torque is applied to move threaded device  602  into the surface in a rotational step-wise manner that corresponds with threads  610  on threaded device  602 . The torque and force exerted by the insertion tool is based at least in part on the configuration of threads  610  and the terrain at the installation location. 
     In some embodiments, threads  610  are configured based on the terrain conditions of the installation location and based on minimum disruption of the terrain during insertion. The pitch of threads  610  are configured to minimize disturbance of the installation location during vertical movement of the threaded device  602  into the surface. For example, if the terrain at the installation location is substantially unconsolidated, such as sandy soil, threads  610  may include wider helical ridges and may include a lower pitch. As another example, if the terrain is substantially inelastic, consolidated, or packed, threads  610  may include narrower helical ridges and a higher pitch. Following installation of threaded device  602  into the installation location, additional degrees of rotation may be applied by the insertion tool to ensure a positive downward force is exerted by the surrounding surface on threaded device  602 . 
     In some embodiments, any of threaded device  602 , receptacle  604 , and cover  606  may be constructed of a material without magnetic properties, such as hard plastic or aluminum. In some embodiments, threaded device  602 , receptacle  604 , and cover  606  are constructed with a material of sufficient hardness or stiffness to minimize or eliminate any resonances at frequencies within the frequencies of the seismic band. Further, threaded device  602  is constructed of a material that withstands insertion at the installation location without substantial deformation. Additionally, threaded device  602  is constructed of a material that facilitates mechanical coupling to the terrain of the earth&#39;s surface at the installation location. In some embodiments, each of threaded device  602 , receptacle  604 , and cover  606  may be constructed of two or more materials. 
     Although discussed with respect to magnetic coupling, in some embodiments, other coupling mechanisms between threaded device  602 , receptacle  604 , and cover  606  may be utilized. For example, receptacle  604  may be substantially affixed to threaded device  602  via screws, fasteners, welds, adhesive, or any other suitable fastening mechanism. The coupling force may be sufficient to maintain the mechanical integrity of the interfaces between the components of the multicomponent sensor assembly. Mechanical integrity may refer to the need to minimize or eliminate any movement of components of the multicomponent sensor assembly relative to each other that allow the components to become loose, rattle, or otherwise individually move. 
     As illustrated in  FIG. 6 , shaft  612  of threaded device  602  may be substantially conically shaped. In some embodiments, shaft  612  may be configured in any suitable shape, for example, shaft  612  may be tapered or may be cylindrically shaped. 
     Although discussed with reference to multicomponent sensors, assembly  600  may be utilized for insertion of any device utilized to determine a property at the installation location. For example, assembly  600  may be utilized with soil content measurement devices, sea level measurement devices, or any other suitable devices. Additionally, the selection of a particular configuration of assembly  600  may be based on the necessary mechanical coupling force, the orientation of the assembly with respect to the terrain at the installation location, the need to interchange or exchange the components for use at another location, characteristics of the terrain at the installation location, or any other suitable factor based on the specific implementation. 
     Embodiments of the present disclosure may be suited for deployment in land surveys or ocean bottom surveys. In ocean bottom implementations, multicomponent sensor assembly  600  may be encased in plastic or other substantially waterproof or water resistant material. 
       FIG. 7  illustrates an example of an active sensor assembly in accordance with some embodiments of the present disclosure. Active sensor assembly  700  includes head  702  and shaft  704 . Head  702  includes sensor  706  and associated components  708  including, for example, a digitizing unit, a radio frequency identification (RFID) tag, a light emitting diodes (LEDs) to indicate unit status, a memory, an antenna, and other suitable components. Head  702  may also include interface  710  for communicating with a collar (discussed with reference to  FIG. 8 ). Configuring sensor  706  inside head  702  minimizes the number of components and complexity of the sensor assembly. 
     Active sensor assembly  700  includes threads  714  on shaft  704  to allow insertion into an installation location, such as the earth&#39;s surface. Active sensor assembly  700  is inserted into the installation location using an insertion tool that is configured to exert the necessary force and torque to ensure that the active sensor assembly  700  travels into the surface with minimum disturbance to the consolidation of the surrounding surface. For example, the force and torque may be applied to move active sensor assembly  700  into the surface in a rotational step-wise manner that corresponds with threads  714  on shaft  704 . The torque and force exerted by the insertion tool is based at least in part on the configuration of threads  714  and the terrain at the installation location. A drive shaft of the insertion tool is configured to mate with head  704 . Although head  704  is illustrated as hexagonal, head  704  may be of any suitable configuration to mate with the drive shaft of the insertion tool. 
     In some embodiments, threads  714  may be configured based on the terrain conditions of the installation location and based on minimum disruption of the terrain during insertion. The pitch of threads  714  are configured to minimize disturbance of the installation location during vertical movement of the active sensor assembly  700  into the surface. For example, if the terrain at the installation location is substantially unconsolidated, such as sandy soil, threads  714  may include wider helical ridges and may include a lower pitch. As another example, if the terrain is substantially inelastic, consolidated, or packed, threads  714  may include narrower helical ridges and a higher pitch. Following installation of active sensor assembly  700  into the installation location, additional degrees of rotation may be applied by the insertion tool to ensure a positive downward force is exerted by the surrounding surface on active sensor assembly  700 . 
     Active sensor assembly  700  may be constructed of hard plastic, aluminum or any other non-metallic or otherwise suitable material. In some embodiments, active sensor assembly  700  is constructed with a material of sufficient hardness or stiffness to minimize or eliminate any resonances at frequencies within the frequencies of the seismic band. In some embodiments, active sensor assembly  700  is constructed of a material that withstands insertion at the installation location without substantial deformation. Additionally, active sensor assembly  700  may be constructed of a material that facilitates mechanical coupling to the terrain of the earth&#39;s surface at the installation location. 
     Shaft  704  of active sensor assembly  700  may be substantially cylindrically shaped and foot  716  of active sensor assembly  700  may be substantially flat. In some embodiments, shaft  704  may be configured in any suitable shape, for example, shaft  704  may be tapered from head  702  to foot  716 . Additionally, foot  716  may be configured in any suitable shape. For example, foot  716  may have a convex shape or may include teeth, flanges, or spikes as suitable for the particular implementation. 
     Active sensor assembly  700  includes a cavity extending substantially through the center of the shaft  704  of active sensor assembly  700  from foot  716  to head  702 . The cavity creates a hollow opening extending partially through active sensor assembly  700 . Use of a cavity assists in ensuring that disturbance to the installation surface is minimized during insertion of active sensor assembly  700 . The thickness of shaft  704  that encompasses the cavity is based on the force or torque required to insert active sensor assembly  700  at the installation location. For example, the thickness of shaft  704  may be sufficient such that active sensor assembly  700  is able to withstand the force or torque required for insertion with insubstantial deformation. 
     In some embodiments, head  702  includes sensor  706 . Sensor  706  is any suitable device that measures or detects a property of the surface or subsurface. In some embodiments, sensor  706  may be any type of instrument that is operable to transform seismic energy or vibrations into a voltage signal. For example, sensor  706  may be a vertical, horizontal, or multicomponent geophone, accelerometers, or optical fiber with wire or wireless data transmission, such as a three component (3C) geophone, a 3C accelerometer, or a 3C Digital Sensor Unit (DSU). Multiple sensors  706  may be utilized within an exploration area to provide data related to multiple locations and distances from seismic sources. Sensors  706  arranged in heads  702  may be positioned in multiple configurations, such as linear, grid, array, or any other suitable configuration. Additionally, in some embodiments, head  702  includes interface  710  communicatively coupled to sensor  706  and components  708 . Interface  710  may be configured to communicate with and receive power from a collar, discussed with reference to  FIG. 8 . 
       FIG. 8  illustrates an example of a collar used with the active sensor assembly of 
       FIG. 7  in accordance with some embodiments of the present disclosure. Collar  800  is configured to fit over head  702  of active sensor assembly  700 . For example, collar  800  may include an opening  802  that mates with the exterior surfaces of head  702 . Additionally, head  702  may be tapered to facilitate a snug but relatively easily removable mating between collar  800  and head  702 . In some embodiments, cables  808  are coupled to and extend from collar  800  to connect sensor  706  with other sensors or a computing system. Cables  808  may provide for power, data, and communication. Additionally, in the event of a communication failure with sensor  706 , the collar  800  using cables  808  may maintain connectivity with adjacent sensors until repairs can be made. 
     Collar  800  may include interface  810  that wirelessly communicates with interface  710  configured on head  702 . As such, interface  810  is communicatively coupled to interface  710 . For example, interfaces  810  and  710  may be contacts, connectors, RFID links, spring loaded contacts, contact strips, or other suitable method for accomplishing wireless power transfer and data communication. Coupling between interfaces  810  and  710  may provide a robust and wireless data link, and method for providing power to sensor  706 . Because of the mechanical fit between interfaces  810  and  710 , the communication and power transfer between collar  800  and active sensor assembly  700  may continue in both wet and dry or abrasive environments. Further, since collar  800  is separate from active sensor assembly  700 , high voltage discharges (static/lightning) may be prevented from damaging sensor  706 . Additionally, in some embodiments, collar  800  may be a ring or any other suitable detachable device. 
       FIG. 9  illustrates a flow chart of example method  900  for installing geophysical sensors for seismic exploration in accordance with some embodiments of the present disclosure. The method  900  begins at step  902 , where an operator determines the soil conditions and terrain at a location for installation of a geophysical sensor in an exploration area for a seismic survey. 
     At step  904 , the operator selects, based on the terrain, the appropriate sensor assembly. For example, geophysical sensor assembly  100  discussed with reference to  FIGS. 1 through 5 , multicomponent sensor assembly  600  discussed with reference to  FIG. 6 , active sensor assembly  700  discussed with reference to  FIGS. 7 and 8 , or any suitable combination may be selected for use. Any of the configurations of  FIGS. 1 through 8  may be utilized based on the need for improved mechanical coupling between the geophysical sensor and the earth&#39;s surface, the availability or cost of any particular assembly, or the ease of installation of a particular assembly. The operator may further based the selection of the sensor assembly based on thread configuration as it relates to the terrain at the installation location, as discussed with reference to  FIGS. 1, 6 and 7 . 
     At step  906 , the operator prepares the installation location for installation of the selected sensor assembly. For example, an excavation tool may be utilized to create a cavity for the installation of the selected sensor assembly as discussed with reference to  FIGS. 4 and 5 . 
     At step  908 , the operator installs the selected sensor assembly. For example, an insertion tool that is configured to mate with a portion of the selected sensor assembly may be utilized for installation. With reference to  FIGS. 1 through 5 , the operator may install threaded device  102 . Then, baseplate  104  affixed to a sensor  402  may be coupled to the installed threaded device  102 . Using threaded device  102  and a specialized insertion tool that is able to exert the necessary force and torque may ensure that threaded device  102  moves into the installation location with as little disturbance of the consolidation of the surrounding media as possible. For example, the insertion tool may couple the force and torque in such a way that the tool moves downward into the media with the same step as the thread on threaded device  102 . The insertion tool may allow measurement of the torque and downward pressure required to insert threaded device  102 . Such measurements may be recorded for each sensor position, and may be used to map very near surface conditions by establishing a correlation between the mechanical measurements and geophysical properties such as ground or surface wave velocity, absorption, and other suitable parameters. At the end of the insertion process, a few extra degrees of rotation may be added, in order to secure a positive downward force being exerted by the media on the device. With reference to  FIG. 6 , threaded device  602 , receptacle  604 , and cover  606  may be installed. Receptacle  604  and cover  606  may be coupled prior to attaching to threaded device  602 , which may include a tapered interface or may include sensors on a vertical axis protruding into threaded device  602 . With reference to  FIGS. 7 and 8 , the operator may install active sensor assembly  700 . Then collar  800  may be coupled to active sensor assembly  700 , and interface  810  may be communicatively coupled to interface  710 . Further, the operator may cover the selected sensor assembly with dirt, debris, or any other suitable material to minimize noise from wind and the environment. 
     Modifications, additions, or omissions may be made to method  900  without departing from the scope of the present disclosure. For example, the order of the steps may be performed in a different manner than that described and some steps may be performed at the same time. For example, step  906  may be performed before step  904 . Additionally, each individual step may include additional steps without departing from the scope of the present disclosure. Further, more steps may be added or steps may be removed without departing from the scope of the disclosure. 
       FIG. 10  illustrates an elevation view of an example seismic exploration system configured to produce images of the earth&#39;s subsurface geological structure in accordance with some embodiments of the present disclosure. The images produced by system  1000  allow for the evaluation of subsurface geology. System  1000  may include one or more seismic energy sources  1002  and one or more sensors  1004  which are located within a pre-determined exploration area. The exploration area may be any defined area selected for seismic survey or exploration. Survey of the exploration area may include the activation of seismic source  1002  that radiates an acoustic wave field that expands downwardly through the layers beneath the earth&#39;s surface. The seismic wave field is then partially reflected from the respective layers and recorded by sensors  1004 . For example, source  1002  generates seismic waves and geophysical sensors  1004  records rays  1006  and  1008  reflected by interfaces between subsurface layers  1010 ,  1012 , and  1014 , oil and gas reservoirs, such as target reservoir  1016 , or other subsurface structures. 
     Seismic energy source  1002  may be referred to as an acoustic source, seismic source, energy source, and source  1002 . In some embodiments, source  1002  is located on or proximate to surface  1020  of the earth within an exploration area. Source  1002  may be operated by a central controller that coordinates the operation of several sources  1002 . Further, a positioning system, such as a global positioning system (GPS), may be utilized to locate and time-correlate sources  1002  and sensors  1004 . Source  1002  may comprise any type of seismic device that generates controlled seismic energy, such as a seismic vibrator, vibroseis, dynamite, an air gun, a thumper truck, or any other suitable seismic energy source. 
     Sensors  1004  may be located on or proximate to surface  1020  of the earth within an exploration area. For example, sensor  1004 - 1  may be located on the surface  1020  while sensors  1004 - 2  and  1004 - 3  may be located in a recess created by an excavation tool. Sensors  1004  may be any type of instrument that is operable to transform seismic energy or vibrations into a voltage signal. For example, sensors  1004  may be vertical, horizontal, or multicomponent geophone, accelerometers, or optical fiber with wire or wireless data transmission, such as a three component (3C) geophone, a 3C accelerometer, or a 3C Digital Sensor Unit (DSU). Multiple sensors  1004  may be utilized within an exploration area to provide data related to multiple locations and distances from sources  1002 . Sensors  1004  may be positioned in multiple configurations, such as linear, grid, array, or any other suitable configuration. In some embodiments, geophysical sensors  1004  may be positioned along one or more cables or strings  1022 . Each sensor  1004  is typically spaced apart from adjacent sensors  1004  in the string  1022 . 
     Spacing between sensors  1004  in string  1022  may be approximately the same preselected distance, or span, or the spacing may vary depending on a particular application, exploration area topology, or any other suitable parameter. Each of sensor  1004  may include all or portions of any of the sensor assemblies discussed with reference to  FIGS. 1 through 8 . 
     One or more sensors  1004  transmit raw seismic data from reflected seismic energy via network  1024  to computing unit  1026 . Computing unit  1026  may perform seismic data processing on the raw seismic data to prepare the data for interpretation, and may also be configured to control sensors  1004 . Computing unit  1026  may include any instrumentality or aggregation of instrumentalities operable to compute, classify, process, transmit, receive, store, display, record, or utilize any form of information, intelligence, or data. For example, computing unit  1026  may include one or more personal computers, storage devices, servers, or any other suitable device and may vary in size, shape, performance, functionality, and price. 
     Network  1024  may be configured to communicatively couple one or more components of system  1000 . For example, network  1024  may communicatively couple sensors  1004  with computing unit  1026 . Further, network  1024  may communicatively couple a particular sensor  1004  with other sensors  1004 . Network  1024  may be any type of network that provides communication, such as one or more of a wireless network, a local area network (LAN), or a wide area network (WAN), such as the Internet. 
     This disclosure encompasses all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend Similarly, where appropriate, the appended claims encompass all changes, substitutions, variations, alterations, and modifications to the example embodiments herein that a person having ordinary skill in the art would comprehend. Moreover, reference in the appended claims to an apparatus or system or a component of an apparatus or system being adapted to, arranged to, capable of, configured to, enabled to, operable to, or operative to perform a particular function encompasses that apparatus, system, component, whether or not it or that particular function is activated, turned on, or unlocked, as long as that apparatus, system, or component is so adapted, arranged, capable, configured, enabled, operable, or operative. For example, a geophysical sensor does not have to be turned on but must be configured to receive reflected energy. 
     Embodiments of the disclosure may also relate to an apparatus for performing the operations herein. This apparatus may be specially constructed for the required purposes. Although the present disclosure has been described with several embodiments, a myriad of changes, variations, alterations, transformations, and modifications may be suggested to one skilled in the art, and it is intended that the present disclosure encompass such changes, variations, alterations, transformations, and modifications as fall within the scope of the appended claims. Moreover, while the present disclosure has been described with respect to various embodiments, it is fully expected that the teachings of the present disclosure may be combined in a single embodiment as appropriate. Instead, the scope of the disclosure is defined by the appended claims.