Patent Publication Number: US-10330551-B2

Title: Pass-throughs for use with sensor assemblies, sensor assemblies including at least one pass-through and related methods

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application is a divisional of U.S. patent application Ser. No. 14/924,033, filed Oct. 27, 2015, now U.S. Pat. No. 9,964,459, issued May 8, 2018, which claims the benefit of U.S. Provisional Patent Application Ser. No. 62/074,517, filed Nov. 3, 2014, the disclosure of each of which is hereby incorporated herein in its entirety by this reference. 
    
    
     TECHNICAL FIELD 
     Embodiments of the present disclosure relate to pass-throughs for use with sensor assemblies and, more particularly, to pass-throughs utilized to bypass one or more portions of a sensor assembly and related assemblies and associated methods. 
     BACKGROUND 
     Thickness shear mode quartz resonator sensors have been used successfully in the downhole environment of oil and gas wells for several decades and are an accurate means of determining downhole pressures in widespread use in hydrocarbon (e.g., oil and gas) exploration and production, as well as in other downhole applications. Quartz resonator pressure sensors typically have a crystal resonator located inside a housing exposed to ambient bottomhole fluid pressure and temperature. Electrodes on the resonator element coupled to a high frequency power source drive the resonator and result in shear deformation of the crystal resonator. The electrodes also detect the resonator response to pressure and temperature and are electrically coupled to conductors extending to associated power and processing electronics isolated from the ambient environment. Ambient pressure and temperature are transmitted to the resonator, via a substantially incompressible fluid within the housing, and changes in the resonator frequency response are sensed and used to determine the pressure and/or temperature and interpret changes in same. For example, a quartz resonator sensor, as disclosed in U.S. Pat. Nos. 3,561,832 and 3,617,780, includes a cylindrical design with the resonator formed in a unitary fashion in a single piece of quartz. End caps of quartz are attached to close the structure. 
     Generally, a pressure transducer comprising a thickness shear mode quartz resonator sensor assembly may include a first sensor in the form of a primarily pressure sensitive thickness shear mode quartz crystal resonator exposed to ambient pressure and temperature, a second sensor in the form of a temperature sensitive quartz crystal resonator exposed only to ambient temperature, a third reference crystal in the form of quartz crystal resonator exposed only to ambient temperature, and supporting electronics. The first sensor changes frequency in response to changes in applied external pressure and temperature with a major response component being related to pressure changes, while the output frequency of the second sensor is used to temperature compensate temperature-induced frequency excursions in the first sensor. The reference crystal, if used, generates a reference signal, which is only slightly temperature-dependent, against or relative to which the pressure-induced and temperature-induced frequency changes in the first sensor and the temperature-induced frequency changes in the second sensor can be compared. Such comparison may be achieved by, for example, frequency mixing frequency signals and using the reference frequency to count the signals from the first and second sensors for frequency measurement. 
     Prior art devices of the type referenced above including one or more thickness shear mode quartz resonator sensors exhibit a high degree of accuracy even when implemented in an environment such as a downhole environment exhibiting high pressures and temperatures. However, when implemented as pressure sensors, the sensors in these devices must be at least partially exposed to the exterior environment surrounding the device. For example, when implemented in a downhole environment, the sensors may be exposed to pressures up to about 30,000 psi (about 206.84 MPa) and temperatures of up to 200° C. Accordingly, in order to comply with such extreme pressure and temperature environments and shifts in pressure and temperature, the housings of such devices enclosing the sensors must be designed and manufactured to be substantially robust as to not fail when implemented in the field exposed to such pressures and temperatures. 
     For example, where pressure transducers are required to at least partially expose one or more pressure sensors within the pressure transducer to the pressure of the external environment (e.g., via a fluid within the sensor), the housing of the transducer must be designed to enable the pressure sensors to be in communication with pressure of the external environment while still maintaining structural integrity and protecting other components of the transducer, such as, for example, reference sensors, temperature sensors, and other electronics in the transducer from the surrounding extreme pressure and temperature environments. In some implementations, it is required to pass connections, such as electrical conductors, along the length of the transducer and past the pressure sensors from one component to another component within or external to the transducer. Thus, passing the electrical conductors past each pressure sensor may be difficult as such connections must be routed through or around portions of one or more pressure housings having the pressure sensors therein and that are equipped to handle the forces from pressures and temperatures of a downhole environment. 
     BRIEF SUMMARY 
     In some embodiments, the present disclosure includes a transducer assembly. The transducer assembly includes at least one sensor and a housing having a longitudinal axis. The housing includes a sensor housing portion at least partially enclosing the at least one sensor in a chamber in the sensor housing portion and a pass-through portion comprising at least one aperture in a portion of the housing extending along the longitudinal axis and the sensor housing portion. 
     In additional embodiments, the present disclosure includes a transducer assembly. The transducer assembly includes at least one sensor and a housing having a longitudinal axis. The housing includes a sensor housing portion at least partially enclosing the at least one sensor in a chamber in the sensor housing portion where the chamber is at least partially offset from the longitudinal axis of the housing and a pass-through portion comprising at least one aperture in a portion of the housing extending along the longitudinal axis and the sensor housing portion. 
     In additional embodiments, the present disclosure includes a transducer assembly. The transducer assembly includes at least one pressure sensor, an electronics assembly, and a housing having a longitudinal axis. The housing includes a pressure housing at least partially enclosing the at least one pressure sensor in a chamber in the pressure housing. The pressure housing includes a thick wall portion positioned on one lateral side of the pressure housing where the thick wall portion has a lateral width taken in a direction transverse to the longitudinal axis of the housing that is greater than a lateral width taken in the direction transverse to the longitudinal axis of the housing of another wall portion of the pressure housing positioned on another lateral side of the pressure housing. The housing further includes an electronics housing having the electronics assembly disposed therein and a pass-through portion comprising at least one aperture in the thick wall portion of the pressure housing and extending along the longitudinal axis of the housing and the pressure housing. The transducer assembly further includes at least one electrical connection electronically coupled to the electronics assembly where the at least one electrical connection extends through the at least one aperture of the pass-through portion to the electronics assembly. 
     In additional embodiments, the present disclosure includes a method of forming a transducer assembly. The method includes welding a first section of the transducer assembly to a second section of the transducer assembly with a width of the weld selected to exceed a required width by a selected dimension, the required width selected in view of one or more of a maximum external pressure and a maximum external temperature to which the transducer is designed to handle during use, and forming at least one aperture in a housing of the transducer assembly extending along a longitudinal axis of the housing and through the weld, the at least one aperture exhibiting a width substantially less than or equal to the selected dimension. 
     In yet additional embodiments, the present disclosure includes a method of forming a transducer assembly. The method includes welding a first housing section of the transducer assembly exhibiting a thick wall portion positioned on one lateral side of a chamber for receiving a pressure sensor to a second housing portion of the transducer assembly, the thick wall portion of the first housing section having a lateral width taken in a direction transverse to a longitudinal axis of the transducer assembly that is greater than a lateral width taken in the direction transverse to the longitudinal axis of the transducer assembly of another wall portion, and forming at least one aperture in the thick wall portion of the first housing section extending along the longitudinal axis of the transducer assembly, along the chamber, and through the weld. 
     In yet additional embodiments, the present disclosure includes sensors and related assemblies and methods of forming and operating sensors and related assemblies as described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       While the specification concludes with claims particularly pointing out and distinctly claiming what are regarded as embodiments of the present disclosure, various features and advantages of embodiments of the disclosure may be more readily ascertained from the following description of example embodiments of the disclosure provided with reference to the accompanying drawings, in which: 
         FIG. 1  is a partial cross-sectional simplified schematic view of a transducer assembly in accordance with an embodiment of the present disclosure; 
         FIG. 2  is another cross-sectional simplified schematic view of the transducer assembly shown in  FIG. 1 ; 
         FIG. 3  is a partial cross-sectional view of a transducer assembly in accordance with an embodiment of the present disclosure; 
         FIG. 4  is a front view of a transducer assembly in accordance with an embodiment of the present disclosure; 
         FIG. 5  is a partial cross-sectional view of the transducer assembly shown in  FIG. 4 ; 
         FIG. 6  is an exploded, partial cross-sectional simplified schematic view of a transducer assembly in accordance with an embodiment of the present disclosure; 
         FIG. 7  is a partial cross-sectional simplified schematic view of the transducer assembly of  FIG. 6  shown during assembly of the transducer assembly; and 
         FIG. 8  is a partial cross-sectional simplified schematic view of the transducer assembly of  FIGS. 6 and 7  shown during assembly of the transducer assembly. 
     
    
    
     DETAILED DESCRIPTION 
     In the following detailed description, reference is made to the accompanying drawings that depict, by way of illustration, specific embodiments in which the disclosure may be practiced. However, other embodiments may be utilized, and structural, logical, and configurational changes may be made without departing from the scope of the disclosure. The illustrations presented herein are not meant to be actual views of any particular sensor, transducer, assembly, or component thereof, but are merely idealized representations that are employed to describe embodiments of the present disclosure. The drawings presented herein are not necessarily drawn to scale unless otherwise indicated. Additionally, elements common between drawings may retain the same numerical designation. 
     Although some embodiments of sensors of the present disclosure are depicted as being used and employed in pressure transducer assemblies utilizing one or more quartz resonator sensors, persons of ordinary skill in the art will understand that the embodiments of the present disclosure may be employed in any assembly or system for measurement of an environment external to one or more sensors where the one or more sensors are at least partially exposed (e.g., in communication with) the exterior environment. 
       FIG. 1  is a partial cross-sectional simplified schematic of a transducer assembly (e.g., pressure transducer  100 ) including a housing  101 . As shown in  FIG. 1 , the housing  101  of the pressure transducer  100  includes a first portion (e.g., pressure housing  102 ) for holding one or more sensors that are at least partially exposed (e.g., entirely exposed, exposed to the pressure and/or temperature of the exterior environment). For example, the pressure transducer  100  may include one or more pressure sensors  104  (e.g., a quartz crystal resonating sensor) disposed in a chamber  106  in the pressure housing  102  that are exposed to the pressure and/or the temperature of the exterior environment. 
     The chamber  106  in the pressure housing  102  may be in communication with an environment exterior to the pressure transducer  100  in order to determine one or more environmental conditions in the exterior environment (e.g., pressure and/or temperature of the exterior environment). For example, the chamber  106  may be in fluid communication with one or more isolation elements  108  (e.g., a diaphragm assembly, a bladder assembly, a bellows assembly, as well as combinations of the foregoing). In some embodiments, isolation element  108  may be configured as a port  109  that is in communication with an exterior environment or fluid where the port  109  may be at least partially isolated proximate the housing  101  (e.g., with a diaphragm disposed in the port  109 ) or at a location away from the housing  101  (e.g., along a fluid channel extending from the housing  101 ). The isolation element  108  acts to transmit pressure and/or temperature exterior to the pressure transducer  100  to sensors within the pressure transducer  100  (e.g., via a fluid within the pressure transducer  100 ). Fluid may be disposed in the chamber  106  around the pressure sensor  104  and, optionally, in the isolation element  108  (e.g., in a bellows) to transmit the pressure and/or temperature from the exterior of the pressure transducer  100 . In some embodiments, the fluid within pressure transducer  100  may comprise a highly incompressible, low thermal expansion fluid such as, for example, oil (e.g., a PARATHERM® or sebacate oil). The pressure and thermal expansion of the fluid may be sensed by the pressure sensor  104  (e.g., a quartz crystal sensing element). 
     As depicted in  FIG. 1  and discussed below in greater detail, the pressure sensor  104  may be positioned along a longitudinal axis L 100  of the pressure transducer  100 . In some embodiments, one or more of the pressure sensor  104  and the chamber  106  may be partially offset (from the longitudinal axis L 100  of the pressure transducer  100 . For example, a longitudinal axis L 104  (e.g., a centerline) of the pressure sensor  104  and/or a longitudinal axis L 106  (e.g., a centerline) of the chamber  106  may be laterally offset from the longitudinal axis L 100  (e.g., centerline) of the pressure transducer  100  (e.g., in a direction transverse to, e.g., perpendicular to, the longitudinal axis L 100 ). In some embodiments, one or more of the pressure sensor  104 , the chamber  106 , and the pressure transducer  100  may have a substantially elliptical (e.g., an ellipse) or circular (e.g., annular, cylindrical) shape and/or cross section and the one or more of the pressure sensor  104  and the chamber  106  may have a centerline that is laterally offset from a centerline of the pressure transducer  100 . In other embodiments, one or more of the pressure sensor  104  and the chamber  106  may be substantially aligned with the longitudinal axis L 100  of the pressure transducer  100 . For example, the longitudinal axes L 104 , L 106  of one or both of the pressure sensor  104  and the chamber  106  may be substantially aligned with the longitudinal axis L 100  of the pressure transducer  100 . 
     An electronics housing  110  is coupled to the pressure housing  102  (e.g., via spacer  114 ). As depicted, the electronics housing  110  includes an electronics assembly  112  that is at least partially isolated from the fluid within the chamber  106  in the pressure housing  102 , which is in communication with the exterior environment. The electronics assembly  112  may be electrically coupled to the pressure sensor  104  in the pressure transducer  100  via electrical connections (e.g., feedthrough pins  116  that extend through the spacer  114 ) and may be utilized to operate (e.g., drive) one or more of the pressure sensor  104  and to receive the output of the pressure sensor  104 . 
     In some embodiments, the pressure sensor  104  may be at least partially sealed in the pressure housing  102  by another portion of the housing  101  (e.g., the spacer  114 ). As depicted, the spacer  114  may form a bulkhead between the electronics housing  110  and the pressure housing  102 . 
     At least a portion of the housing  101  of the pressure transducer  100  comprises a pass-through portion (e.g., a feedthrough portion) including one or more pass-through apertures  118  extending through a portion of the housing  101  (e.g., the pressure housing  102  and the spacer  114 ). The pass-through aperture  118  may be used to pass a connection (e.g., one or more electrical connections  120 ) past the pressure housing  102 . For example, the electrical connection  120  may extend through the pass-through aperture  118  from another component of the pressure transducer  100  (e.g., another sensor, another electronics assembly, a power source, etc.), and/or a component external to the pressure transducer  100 , along the longitudinal axis L 100  of the pressure transducer  100 , along the pressure housing  102  and the spacer  114 , and to the electronics assembly  112  in the electronics housing  110 . Such a configuration may enable one or more connections to be passed along the longitudinal axis L 100  of the pressure transducer  100  while being at least partially isolated from the pressure housing  102  (e.g., from the fluid and/or pressure sensor  104  that is at least partially exposed to the exterior environment as discussed above). 
       FIG. 2  is another cross-sectional simplified schematic view of a portion of the housing  101  (e.g., the pressure housing  102 ) of the pressure transducer  100  shown in  FIG. 1  taken in a direction transverse to the longitudinal axis L 100  ( FIG. 1 ) of the pressure transducer  100 . As shown in  FIG. 2 , the pressure housing  102  includes the pass-through aperture  118  on one side of the pressure housing  102 . The pressure housing  102  also includes the chamber  106  for receiving the pressure sensor  104  ( FIG. 1 ). As depicted, the chamber  106  is laterally offset in the pressure housing  102 . For example, the centerline of the chamber  106  (e.g., which may coincide with the longitudinal axis L 106  of the chamber  106 ) is offset from the centerline of pressure housing  102  (e.g., which may coincide with the longitudinal axis L 100  of the pressure transducer  100 ). As can be seen in  FIGS. 1 and 2 , the pressure sensor  104  in the chamber  106  will also be offset due to the offset of the chamber  106 . 
     In order to accommodate the pass-through aperture  118  extending through the housing  101 , one or more portions of the housing  101  (e.g., the pressure housing  102 ) may include a first wall portion  122  (e.g., a thick or enlarged walled portion) having a first dimension D 122  (e.g., width, thickness, taken in a direction transverse (e.g., perpendicular) to the longitudinal axis L 100  ( FIG. 1 ) of the pressure transducer  100 ) that is greater than a second dimension D 124  (e.g., width, thickness, taken in a direction transverse (e.g., perpendicular) to the longitudinal axis L 100  ( FIG. 1 ) of the pressure transducer  100 ) of a second adjacent (e.g., opposing) wall portion  124  (e.g., a thin or normal walled portion) of the housing  101 . For example, the first wall portion  122  and the second wall portion  124  may be positioned about the chamber  106  (e.g., at opposing sides of the chamber  106 ) where the walls of the pressure housing  102  extending between the first wall portion  122  and the second wall portion  124  taper between the two thicknesses D 122 , D 124 . As discussed below in greater detail, such varying wall thicknesses may allow the pressure housing  102  to accommodate the pass-through aperture  118  on one side of the pressure housing  102  while still providing a minimum wall thickness surrounding the chamber  106  that can withstand the external forces applied to the pressure housing  102  and/or enable the required connection to (e.g., weld to) another portion of the housing  101  (e.g., the spacer  114  ( FIG. 1 )). 
       FIG. 3  is a partial cross-sectional view of a transducer assembly (e.g., pressure transducer  200 ) that may be similar to and include the same or similar features of the pressure transducer  100  shown and described above with reference to  FIGS. 1 and 2 . As shown in  FIG. 3 , the pressure transducer  200  may include a pressure housing  202  and one or more pressure sensors  204  disposed in a chamber  206  in the pressure housing  202  that are exposed to the pressure and/or the temperature of the exterior environment. As above, the chamber  206  may be offset from a longitudinal axis L 200  of the pressure transducer  200  and may be configured to exhibit one or more of an elliptical, annular, cylindrical, and circular shape and/or cross section. The pressure transducer  200  may include a cap (e.g., spacer  214  including a flange portion  215 ) that is at least partially received in the chamber  206  (e.g., a protrusion of the spacer  214  surrounded by the flange portion  215  is received in the chamber  206 ) and one or more pass-through pins  216  extending through the spacer  214 . The spacer  214  may be coupled to the pressure housing  202  via a welding process coupling at least the flange portion  215  of the spacer  214  to the pressure housing  202 , such as that discussed below with reference to  FIGS. 6 through 8 . 
     The chamber  206  of the pressure housing  202  may be in fluid communication with one or more isolation elements  208  (e.g., a diaphragm assembly, a bladder assembly, a bellows assembly, as well as combinations of the foregoing) via channel  209 . The channel  209  and the chamber  206  may be filled with a fluid (e.g., via fill port  217 ) that transmits pressure and/or temperature to the pressure sensor  204  from the isolation element  208 . 
     As depicted, the isolation element  208  may be housed in isolation housing  207  that is coupled to the pressure housing  202 . For example, the isolation housing  207  may be coupled to the pressure housing  202  via a welding process similar to the welding process coupling the spacer  214  and pressure housing  202  discussed below with reference to  FIGS. 6 through 8 . In other embodiments, the isolation housing  207  may be otherwise coupled to the pressure housing  202  in any other suitable manner (e.g., via threading). 
     The isolation element  208  (e.g., bellows) may be in communication with the environment exterior to the pressure transducer  200  via chamber  211 . In some embodiments, the chamber  211  may be in communication with the external environment (e.g., a fluid of the wellbore may fill the chamber  211 ). In other embodiments, the chamber  211  may contain a fluid (e.g., for transmitting pressure to the isolation element  208 ) that is contained in the chamber  211  and is at least partially isolated from the environment exterior to the pressure transducer  200  with another isolation element  213  (e.g., a diaphragm) positioned in a sidewall of housing  202  of the pressure transducer  200 . 
     As depicted, the pressure transducer  200  may further include an electronics housing  210  that is coupled to the pressure housing  202  (e.g., via the spacer  214 ). The electronics housing  210  includes an electronics assembly  212  that is at least partially isolated from the fluid within the chamber  206  in the pressure housing  202  that is in communication with the exterior environment. In some embodiments, housing  201  may include one or more attachment features  228  for coupling the pressure transducer  200  to adjacent components in a downhole system (e.g., other downhole monitoring components, communication relays for transmitting power to and data from the pressure transducer  200 ). 
     As further depicted in  FIG. 3 , the pressure transducer  200  may include one or more additional sensors that are utilized along with the pressure sensor  204  to determine and compensate for environmental conditions affecting output of the pressure sensor  204 , as well as providing a reference signal. For example, the pressure transducer  200  may include a temperature sensor  230  that is at least partially isolated from (e.g., by the spacer  214  acting as a bulkhead) the fluid within the pressure housing  202  that is in communication with the exterior environment. The temperature sensor  230  is utilized to sense the temperature of the exterior environment (e.g., as is it transmitted to temperature sensor  230  through the housing  201  of the pressure transducer  200  and/or through fluid in the pressure transducer  200 ) to enable compensation for temperature-induced inaccuracies in the output of pressure sensor  204 . 
     In some embodiments, the pressure transducer  200  may include a reference sensor  232  that is isolated from (e.g., by the spacer  214 ) the fluid within the pressure housing  202  that is in communication with the exterior environment. As known in the art, an output of such a reference sensor  232  may be utilized for comparison with other sensors (e.g., the pressure sensor  204 , the temperature sensor  230 , or combinations thereof). For example, one or more of pressure-induced and temperature-induced frequency changes in the one or more of the pressure sensor  204  and the temperature sensor  230  (e.g., in a quartz crystal resonator sensing element of the respective sensors  204 ,  230 ) may be detected by monitoring variations in frequency of the sensors  204 ,  230  with respect to a frequency of the reference sensor  232  (e.g., also including a reference quartz crystal resonator). Data relating to frequency differences detected by the sensors  204 ,  230 ,  232  may be manipulated by the electronics assembly  212  or by electrical equipment at the surface of the wellbore to provide pressure and/or temperature data to an operator monitoring wellbore conditions. 
     At least a portion of the housing  201  of the pressure transducer  200  comprises a pass-through portion including one or more pass-through apertures  218  extending through a portion of the housing  201 . For example, the pass-through aperture  218  may extend along the longitudinal axis L 200  of the pressure transducer  200  through a portion of the housing  201  at least partially exposed to an external environment (e.g., an external pressure), such as, for example, the pressure housing  202 , the isolation housing  207  and the spacer  214 . As above, the pass-through aperture  218  may be used to pass a connection (e.g., one or more electrical connections  120  ( FIG. 1 )) from another component of the pressure transducer  200  or from a component external to the pressure transducer  200  along the longitudinal axis L 200  of the pressure transducer  200 , past and along the isolation housing  207 , the pressure housing  202 , and the spacer  214 , and to the electronics assembly  212  in the electronics housing  210 . Such a configuration may enable one or more connections to be passed along the longitudinal axis L 200  of the pressure transducer  200  while being at least partially isolated from the portions of the pressure transducer  200  exposed to the external environment. 
       FIG. 4  is a front view of a transducer assembly (e.g., pressure transducer  300 ) and  FIG. 5  is a partial cross-sectional view of a transducer assembly. In some embodiments, the pressure transducer  300  may be similar to and include the same or similar features of the pressure transducers  100 ,  200  shown and described above with reference to  FIGS. 1 through 3 . As shown in  FIG. 4 , housing  301  of the pressure transducer  300  may include a pressure housing  302 , which may include one or more sensors that are at least partially exposed to the exterior environment as discussed below, coupled to an electronics housing  310 , which may include electronics and other sensors that are at least partially isolated from the exterior environment as also discussed below. 
     As depicted, the housing  301  may include one or more isolation elements  308  disposed on an exterior portion (e.g., wall, outer surface) of the housing  301  (e.g., extending through a sidewall of the pressure housing  302 ) that are also in communication with an interior portion of the housing  301  (e.g., with chambers holding or in communication with sensors as detailed below). In some embodiments, the isolation elements  308  may be diaphragms (e.g., oval diaphragms) such as those described in, for example, U.S. Pat. No. 8,333,117, to Brown et al., the disclosure of which is hereby incorporated herein in its entirety by this reference. 
     In some embodiments, each isolation element  308  may be in communication with differing portions of the downhole assembly to separately monitor the environmental conditions in the different portions. For example, one isolation element  308  may be in communication with an environment within a string of tubular components (e.g., a production string) positioned in a wellbore annulus and another isolation element may be in communication with an environment in an annulus between the string in the wellbore annulus and the wellbore itself (e.g., between the string and a casing or liner string adjacent the wall of the wellbore). 
     As shown in  FIG. 5 , the pressure transducer  300  may include a pressure housing  302  and one or more pressure sensors  304 . For example, the pressure transducer includes multiple pressure sensors (e.g., two pressure sensors  304 A,  304 B) disposed in one or more chambers  306  (e.g., chambers  306 A,  306 B) in the pressure housing  302  that are both exposed to the pressure and/or the temperature of the exterior environment. As above, each chamber  306 A,  306 B may be offset from a longitudinal axis L 300  of the pressure transducer  300  and may exhibit one or more of an elliptical, annular, cylindrical, and circular shape and/or cross section. 
     The pressure transducer  300  may include one or more caps at either end of the pressure housing  302 . For example, spacer  314 A including a flange portion  315 A may be at least partially received in the chamber  306 A and one or more feedthrough pins  316 A may extend through the spacer  314 A at a first end of the pressure housing  302  proximate the electronics housing  310 . Spacer  314 B including a flange portion  315 B may be at least partially received in the chamber  306 B and one or more feedthrough pins  316 B may extend through the spacer  314 B at a second end of the pressure housing  302  (e.g., opposing the first end) proximate an end of the pressure transducer  300  that may be coupled to one or more other downhole components. Each spacer  314 A,  314 B may be coupled to the pressure housing  302  via a welding process coupling at least the flange portion  315 A,  315 B of each spacer  314 A,  314 B to the pressure housing  302 , such as that discussed below with reference to  FIGS. 6 through 8 . 
     Each chamber  306 A,  306 B of the pressure housing  302  may be in fluid communication with the isolation elements  308  ( FIG. 4 ) formed in the sidewall of the pressure housing  302  of the pressure transducer  300 . For example, each chamber  306 A,  306 B may be in communication with one isolation element  308 . In some embodiments, each chamber  306 A,  306 B may extend through a sidewall of the pressure housing  302  to an exterior of the housing  301  and the isolation elements  308  may each extend over a respective chamber  306 A,  306 B at the outer surface of the housing  301  to seal the chamber  306 A,  306 B. As above, each chamber  306 A,  306 B may be filled with a fluid (e.g., via a respective fill port  317 ) that transmits pressure and/or temperature to the pressure sensor  304 A,  304 B from the isolation element  308 . 
     As depicted, the pressure transducer  300  may further include electronics housing  310  that is coupled to the pressure housing  302  (e.g., via the spacer  314 A). The electronics housing  310  includes an electronics assembly  312 A,  312 B (e.g., one electronics assembly  312 A,  312 B for each pressure sensor  304 A,  304 B) that is at least partially isolated from the fluid within the chamber  306 A,  306 B in the pressure housing  302  that is in communication with the exterior environment. 
     The electronics housing  310  of the pressure transducer  300  may include one or more additional sensors that are utilized along with the pressure sensor  304 A,  304 B to determine and compensate for environmental conditions affecting output of the pressure sensor  304 A,  304 B, as well as providing a reference signal. The pressure transducer  300  may include a temperature sensor  330  that is at least partially isolated from (e.g., by the spacer  314 A acting as a bulkhead) the fluid within the pressure housing  302  that is in communication with the exterior environment. 
     In some embodiments, the pressure transducer  300  may include a reference sensor  332  that is isolated from (e.g., by the spacer  314 A) from the fluid within the pressure housing  302  that is in communication with the exterior environment. 
     At least a portion of the housing  301  of the pressure transducer  300  comprises a pass-through portion including one or more pass-through apertures  318  extending through a portion of the housing  301 . For example, the pass-through aperture  318  may extend along the longitudinal axis L 300  of the pressure transducer  300  through a portion of the housing  301  at least partially exposed to an external environment (e.g., an external pressure), such as, for example, the pressure housing  302  and the spacers  314 A,  314 B on either side of the pressure housing  302 . As above, the pass-through aperture  318  may be used to pass a connection (e.g., one or more electrical connections  120  ( FIG. 1 )) from another component of the pressure transducer  300  along the longitudinal axis L 300  of the pressure transducer  300 , past and along the pressure housing  302  and the spacers  314 A,  314 B, and to one or more of the electronics assemblies  312 A,  312 B in the electronics housing  310 . Such a configuration may enable one or more connections to be passed along the longitudinal axis L 300  of the pressure transducer  300 , while being at least partially isolated from the portions of the pressure transducer  300  exposed to the external environment. For example, an electrical connection between the electronics assembly  312 B and the pressure sensor  304 B (e.g., which electronics assembly  312 B drives and monitors a frequency response of the pressure sensor  304 B) may be passed through the pass-through aperture  318  while being isolated from the chambers  306 A,  306 B. 
       FIG. 6  is an exploded, partial cross-sectional view of a transducer assembly (e.g., pressure transducer  400 ) that may be similar to pressure transducers  100 ,  200 ,  300  discussed above in relation to  FIGS. 1 through 5 . As shown in  FIG. 6 , the pressure transducer  400  may include a pressure housing  402  and one or more pressure sensors  104  disposed in a chamber  406  in the pressure housing  402  that are exposed to the pressure and/or the temperature of the exterior environment. The pressure transducer  400  may include a cap (e.g., spacer  414  including a flange portion  415 ) that may be at least partially received in the chamber  406  and one or more feedthrough pins  116  extending through the spacer  414 . The chamber  406  of the pressure housing  402  may be in fluid communication with one or more isolation elements  408  (e.g., a diaphragm assembly, a bladder assembly, a bellows assembly, as well as combinations of the foregoing) via channel  409 . 
       FIG. 7  is a partial cross-sectional view of the transducer assembly  400  of  FIG. 6  shown during assembly of the pressure transducer  400 . As shown in  FIG. 7 , the pressure sensor  104  is received the chamber  406  in the pressure housing  402 . Spacer  414  is attached to the pressure housing  402  at at least the flange portion  415  surrounding a protrusion  419  of the spacer  414  that is received in the chamber  406 . For example, spacer  414  is welded to the pressure housing  402  (e.g., along the flange portion  415 ) to at least partially (e.g., entirely) seal the pressure sensor  104  within the chamber  406 . Weld  426  (e.g., weld bead) may be disposed about the pressure transducer  400  at an interface between the spacer  414  and the pressure housing  402 . In embodiments where a welded joint is implemented, the welding process may comprise one or more of a gas metal arc welding process (MIG), a gas tungsten arc welding process (TIG), other types of fusion welding process (e.g., an electron-beam welding process (EBW), laser beam welding), and other types of welding. 
     As depicted, the depth or thickness of the weld  426  may be selected to be larger than is required by the environmental conditions (e.g., pressure and/or temperature) in which the pressure transducer  400  is designed to operate. In other words, the depth or thickness of the weld  426  may be selected to extend a distance greater than the depth or thickness that is required by the maximum pressure and/or temperature in which the pressure transducer  400  is designed to operate. For example, the depth or thickness of the weld  426  may be selected to extend a distance substantially equal to or greater than a thickness (e.g., diameter) of one or more apertures in the pressure housing  402  (e.g., aperture  418  ( FIG. 8 )). In some embodiments, the depth or thickness of the weld  426  may be selected to extend a distance substantially equal to or greater than the thickness of a first wall portion  422  (e.g., a thick walled portion) of the pressure housing  402  and to substantially exceed the thickness of a second adjacent wall portion  424  (e.g., a thin walled portion) of the pressure housing  402 . In some embodiments, the depth or thickness of the weld  426  may be selected to extend a distance substantially equal to or greater than the thickness of a second adjacent wall portion  424  (e.g., a thin walled portion) of the pressure housing  402  plus a thickness or width of an aperture (e.g., aperture  418 , discussed below) formed in the first wall portion  422 . 
       FIG. 8  is another partial cross-sectional view of the transducer assembly  400  of  FIGS. 6 and 7  shown during assembly of the pressure transducer  400 . As shown in  FIG. 8 , after the spacer  414  is welded to the pressure housing  402 , one or more apertures  418  may be formed (e.g., machined by drilling, milling, etc.) in and extend along the pressure transducer  400  (e.g., along and through the pressure housing  402 , the spacer  414 , and a portion of the weld  426  between the spacer  414  and the pressure housing  402 ). As discussed above, such one or more apertures  418  may be utilized to pass connections (e.g., electrical connections past the pressure housing  402 ). 
     In some embodiments, pressure transducers in accordance with the instant disclosure may include methods of fabrication, orientations, quartz structures, electronics, assemblies, housings, reference sensors, and components similar to the sensors and transducers disclosed in, for example, U.S. Pat. No. 6,131,462 to EerNisse et al., U.S. Pat. No. 5,471,882 to Wiggins, U.S. Pat. No. 5,231,880 to Ward et al., U.S. Pat. No. 4,550,610 to EerNisse et al., and U.S. Pat. No. 3,561,832 to Karrer et al., the disclosure of each of which patents is hereby incorporated herein in its entirety by this reference. 
     As mentioned above, sensors as disclosed herein (e.g., pressure sensors) may comprise a quartz crystal sensing element. In some embodiments, such a pressure transducer having a quartz crystal pressure sensor (e.g., such as that described in U.S. Pat. No. 6,131,462 to EerNisse et al.) may also include a quartz crystal reference sensor and a quartz crystal temperature sensor that are utilized in comparing the outputs of the crystal sensors (e.g., via frequency mixing and/or using the reference frequency to count the signals from the other two crystals) for temperature compensation and to prevent drift and other pressure signal output anomalies. In other embodiments, one or more of the sensors (e.g., the temperature sensor) may comprise an electronic sensor (e.g., a silicon temperature sensor using, for example, integrated electronic circuits to monitor temperature rather than a sensor exhibiting temperature-dependent variable mechanical characteristics (e.g., frequency changes of a resonator element) such as a quartz crystal resonator). For example, the sensor configurations may be similar to those described in U.S. patent application Ser. No. 13/934,058, filed Jul. 2, 2013, the disclosure of which is hereby incorporated herein in its entirety by this reference, which application describes the use of an electronic temperature sensor in a pressure transducer. 
     In yet additional embodiments, the pressure sensors may comprise a dual-mode sensor configured to sense both pressure and temperature, for example, such as those described in U.S. patent application Ser. No. 13/839,238, filed Mar. 15, 2013, now U.S. Pat. No. 9,528,896, issued Dec. 27, 2016, the disclosure of which is hereby incorporated herein in its entirety by this reference. 
     Embodiments of the present disclosure may be particularly useful in providing transducers (e.g., pressure transducers) that are at least partially exposed to the exterior environment and still enable the ability to pass connections from one component of the transducer or between multiple transducers or other components through (e.g., within) the housing of the transducer. Conventionally, such connections are required to be passed around one or more portions of a housing of the transducer (i.e., outside and external to the housing of the transducer) that are exposed to the exterior environment (e.g., a pressure housing) due to the structural and/or sealing constraints imposed by such transducers. As will be appreciated, such transducers including external connections generally are required to have relatively larger diameters or cross-sectional areas than transducers in accordance with the instant disclosure that enable the ability to pass conductors through an internal pass-through of the sensor. In downhole applications, such a pass-through portion in a transducer housing may enable the overall size of a transducer assembly to be reduced, enabling other components of a downhole tool to utilize the space and/or enabling more efficient production of current, smaller wellbore diameter wells as well as exploration of new, more challenging formations using so-called “slimhole” drilling techniques with small diameter drilling strings and bottomhole components. For example, relatively smaller transducers also enable the ability to pass wires past the transducer between components above and below such transducers when disposed in a drill string in ways that were not possible before with conventional sized transducers. 
     While the disclosure may be susceptible to various modifications and alternative forms, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, it should be understood that the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure encompasses all modifications, variations, combinations, and alternatives falling within the scope of the disclosure as defined by the following appended claims and their legal equivalents.