Explosive environment termination of wellhead cables

Abstract

Technologies are generally described for apparatus, systems, and methods to reduce cost and simplify couplings for wellhead equipment and related cable assemblies. The wellhead equipment is placed on a well that is bored into the ground. The wellhead cable may employ a splice assembly that includes a downhole cable, a surface cable, and a conduit. The surface cable is spliced with the downhole cable below a wellhead hanger. The conduit may be configured to contain the surface cable and terminate in the explosion-proof conduit box located at the surface. An inner space of the conduit may be sealed below the wellhead hanger. The conduit may be break-free, or contiguous, between the wellhead hanger and the explosion-proof box.

What is claimed is: 
     
         1 . A wellhead cable splice assembly comprising:
 a downhole cable;   a surface cable spliced with the downhole cable below a wellhead hanger; and   a conduit configured to contain the surface cable and to terminate in an explosion-proof conduit box on the surface, wherein
 an inner space of the conduit is sealed below the wellhead hanger, and 
 the conduit is break-free between the wellhead hanger and the explosion-proof conduit box. 
   
     
     
         2 . The wellhead cable splice assembly of  claim 1 , further comprising:
 a fitting to secure the conduit to a top surface of the wellhead; and   another fitting to secure the conduit to the explosion-proof conduit box.   
     
     
         3 . The wellhead cable splice assembly of  claim 2 , wherein the fitting and the other fitting are threaded fittings. 
     
     
         4 . The wellhead cable splice assembly of  claim 1 , wherein the inner space of the conduit is sealed below the wellhead hanger through one or more O-rings. 
     
     
         5 . The wellhead cable splice assembly of  claim 1 , wherein the inner space of the conduit is sealed below the wellhead hanger through a sealing tape wound around a top portion of the downhole cable. 
     
     
         6 . The wellhead cable splice assembly of  claim 1 , wherein an outer diameter of the conduit is selectable to fit into an existing wellhead hanger. 
     
     
         7 . The wellhead cable splice assembly of  claim 1 , wherein the surface cable is #4 American Wire Gauge (AWG) cable covered by Polyetheretherketone (PEEK) insulator. 
     
     
         8 . The wellhead cable splice assembly of  claim 1 , wherein the surface cable and the downhole cable are spliced through a crimped or crimp-free connection. 
     
     
         9 . The wellhead cable splice assembly of  claim 1 , further comprising a downhole connector configured to withstand one or more of downhole pressures and an explosion within the explosion-proof conduit box. 
     
     
         10 . A method to form a wellhead cable splice assembly, the method comprising:
 electrically coupling of a downhole cable and a surface cable through a crimped or crimp-free contact;   providing the surface cable through a conduit, wherein a downhole termination of the conduit is coupled to a downhole connector;   providing the conduit through a wellhead hanger to an explosion-proof conduit box on the surface;   securing the conduit through a fitting to a top surface of the wellhead hanger; and   securing the conduit through another fitting to the explosion-proof conduit box.   
     
     
         11 . The method of  claim 10 , further comprising:
 sealing an inside space of the conduit through one or more O-rings below the wellhead hanger.   
     
     
         12 . The method of  claim 10 , further comprising:
 sealing an inside space of the conduit through a sealing tape wound around a top portion of the downhole cable below the wellhead hanger.   
     
     
         13 . A wellhead cable system to electrically couple surface equipment to in-well equipment that is located below a surface of a wellhead hanger of a wellhead, the wellhead cable system comprising:
 an explosion-proof conduit box that located above the surface;   a conduit that includes first and second ends, wherein a first end of the conduit is sealed at the explosion-proof box, a second end of the conduit is sealed at the wellhead, and the conduit contiguously extends from the explosion-proof conduit box to the wellhead;   a downhole cable that includes a first end and a second end, wherein the first end of the downhole cable is configured to electrically couple to the in-well equipment below the wellhead;   a surface cable that includes a first end and a second end, wherein the first end of the surface cable is configured to couple to surface equipment within the explosion-proof conduit box, the second end of the surface cable is spliced to the second end of the downhole cable either within the wellhead hanger or in the wellhead, and surface cable contiguously extends from the exposition-proof conduit box to the wellhead hanger or the wellhead within the conduit.   
     
     
         14 . The wellhead cable system of  claim 13 , wherein the second end of the conduit is secured and sealed within bores of the wellhead hanger. 
     
     
         15 . The wellhead cable system of  claim 13 , wherein the send end of the conduit is secured and sealed within existing features of the wellhead. 
     
     
         16 . The wellhead cable system of  claim 13 , further comprising a uni-directional pressure block that is inserted within the bores of the wellhead hanger and configured to splice each individual conductor of the surface cable to each corresponding conductor of the downhole cable. 
     
     
         17 . The wellhead cable system of  claim 13 , further comprising a uni-directional pressure block that is inserted within existing features of the wellhead hanger and configured to splice each individual conductor of the surface cable to each corresponding conductor of the downhole cable. 
     
     
         18 . The wellhead cable system of  claim 1 , wherein the surface cable and the downhole cable are spliced through either a crimped or crimp-free connection. 
     
     
         19 . The wellhead cable splice assembly of  claim 1 , wherein the in-well equipment corresponds to a submersible downhole pump. 
     
     
         20 . The wellhead cable splice assembly of  claim 1 , wherein the surface equipment corresponds to one or more of a pump, a compressor, or a filter.