Cement head with movable plug cage and pressure balanced plug launch indicator

Abstract

A cement head is disclosed that includes a cement head body that houses a moveable cage which protects a cement plug until the cement plug is released into a cement flow path. The cage is moveable between a first position in which cement slurry flows around the cage, and a second position in which cement slurry flows through the cage to facilitate launch of the cement plug into a wellbore. The cage may include a lifting device to assist with moving the cage from the second position to the first position after launch of the cement plug. The cement head may be a modular design that includes multiple cement head bodies, and may also include a pressure balanced plug launch indicator and torque keys.

What is claimed is: 
     
         1 . A cement head, comprising:
 a cap including an opening that receives a fluid;   a cement head body connected to the cap;   a cage located within the cement head body and configured to receive a plug; and   a plug launch indicator,   wherein the cage is configured to move between a first position and a second position.   
     
     
         2 . The cement head of  claim 1 , wherein, in the first position of the cage, the fluid follows a first flow path around an outside of the cage and, in the second position of the cage, the fluid follows a second flow path through an inside of the cage. 
     
     
         3 . The cement head of  claim 1 , further comprising a lid located within the cap that diverts the fluid flowing into the cap. 
     
     
         4 . The cement head of  claim 1 , wherein the plug launch indicator includes at least one sealing element at one end of the plug launch indicator and at least one sealing element at an opposite end of the plug launch indicator to pressure balance the plug launch indicator. 
     
     
         5 . The cement head of  claim 4 , wherein the at least one sealing element at the one end of the plug launch indicator and the at least one sealing element at the opposite end of the plug launch indicator are a same size. 
     
     
         6 . The cement head of  claim 1 , further comprising a casing adapter connected to the cement head body and configured to connect the cement head body to a work string. 
     
     
         7 . The cement head of  claim 1 , wherein the cement head body or the cap includes at least one key that locks relative rotation between the cement head body and the cap. 
     
     
         8 . The cement head of  claim 1 , wherein a lifting device is connected to the cage and configured to move the cage from the second position to the first position. 
     
     
         9 . The cement head of  claim 8 , wherein the lifting device includes a biasing assembly that automatically moves the cage from the second position to the first position. 
     
     
         10 . The cement head of  claim 1 , further comprising a downstream cement head body connected to a downstream end of the cement head body, wherein the downstream cement head body includes a downstream cage configured to receive an additional plug and configured to move between a first position of the downstream cage and a second position of the downstream cage. 
     
     
         11 . The cement head of  claim 10 , wherein the downstream cement head body includes a downstream plug launch indicator, the downstream plug launch indicator including at least one sealing element at one end of the downstream plug launch indicator and at least one sealing element at an opposite end of the downstream plug launch indicator to pressure balance the downstream plug launch indicator. 
     
     
         12 . The cement head of  claim 11 , wherein the at least one sealing element at the one end of the downstream plug launch indicator and the at least one sealing element at the opposite end of the downstream plug launch indicator are a same size. 
     
     
         13 . The cement head of  claim 10 , wherein a downstream cage lifting device is connected to the downstream cage and configured to move the downstream cage from the second position of the downstream cage to the first position of the downstream cage. 
     
     
         14 . A cement head, comprising:
 a cap including an opening that receives a fluid;   a cement head body connected to the cap;   a cage located within the cement head body and configured to receive a plug; and   a plug launch indicator,   wherein the plug launch indicator includes at least one sealing element at one end of the plug launch indicator and at least one sealing element at an opposite end of the plug launch indicator to pressure balance the plug launch indicator.   
     
     
         15 . The cement head of  claim 14 , wherein the at least one sealing element at the one end of the plug launch indicator and the at least one sealing element at the opposite end of the plug launch indicator are a same size. 
     
     
         16 . The cement head of  claim 14 , wherein the cage is configured to move between a first position and a second position. 
     
     
         17 . The cement head of  claim 16 , wherein, in the first position of the cage, the fluid follows a first flow path around an outside of the cage and, in the second position of the cage, the fluid follows a second flow path through an inside of the cage. 
     
     
         18 . The cement head of  claim 16 , wherein a lifting device is connected to the cage and configured to move the cage from the second position to the first position. 
     
     
         19 . The cement head of  claim 18 , wherein the lifting device includes a biasing assembly that automatically moves the cage from the second position to the first position. 
     
     
         20 . The cement head of  claim 14 , further comprising a lid located within the cap that diverts the fluid flowing into the cap. 
     
     
         21 . The cement head of  claim 14 , further comprising a casing adapter connected to the cement head body and configured to connect the cement head body to a work string. 
     
     
         22 . The cement head of  claim 14 , wherein the cement head body or the cap includes at least one key that locks relative rotation between the cement head body and the cap. 
     
     
         23 . The cement head of  claim 14 , further comprising a downstream cement head body connected to a downstream end of the cement head body, wherein the downstream cement head body includes a downstream plug launch indicator, the downstream plug launch indicator including at least one sealing element at one end of the downstream plug launch indicator and at least one sealing element at an opposite end of the downstream plug launch indicator to pressure balance the downstream plug launch indicator. 
     
     
         24 . The cement head of  claim 23 , wherein the downstream cement head body includes a downstream cage configured to receive an additional plug and configured to move between a first position of the downstream cage and a second position of the downstream cage. 
     
     
         25 . The cement head of  claim 24 , wherein a downstream cage lifting device is connected to the downstream cage and configured to move the downstream cage from the second position of the downstream cage to the first position of the downstream cage. 
     
     
         26 . A method of launching a plug from a cement head, the cement head including, a cap having an opening that receives a fluid, a cement head body connected to the cap, a cage located within the cement head body and configured to receive the plug, and a plug launch indicator, the method comprising:
 positioning the cage in an initial position within the cement head body; loading the plug into an internal bore of the cage; attaching the cap to the cement head body; pumping the fluid through the opening of the cap such that the fluid flows around an outside of the cage; and releasing the cage such that the cage moves from the initial position to a launch position,   wherein, in the launch position, the fluid is redirected by the cage from flowing around the outside of the cage to flowing through the internal bore of the cage to push the plug out of the cage;   wherein the fluid flowing through the internal bore of the cage launches the plug from the cage and into the cement head body; and   wherein the plug moves through the cement head body and contacts the plug launch indicator to actuate the plug launch indicator.   
     
     
         27 . The method of  claim 26 , wherein the plug launch indicator includes at least one sealing element at one end of the plug launch indicator and at least one sealing element at an opposite end of the plug launch indicator to pressure balance the plug launch indicator. 
     
     
         28 . The method of  claim 26 , wherein the cap or the cement head body includes at least one key that locks relative rotation between the cement head body and the cap, and the attaching of the cap to the cement head body includes: aligning the key on one of the cap or the cement head body with a key pocket on another of the cap and the cement head body and inserting the key into the key pocket. 
     
     
         29 . The method of  claim 26 , further comprising operating a lifting device that is connected to the cage to move the cage from the launch position to the initial position. 
     
     
         30 . The method of  claim 26 , further comprising removing the cap to move the cage from the launch position to the initial position. 
     
     
         31 . The method of  claim 30 , wherein a lifting device that includes a biasing assembly automatically moves the cage from the launch position to the initial position when the cap is removed. 
     
     
         32 . The method of  claim 26 , wherein the cement head further includes a downstream cement head body connected to a downstream end of the cement head body, the downstream cement head body including a downstream cage and a downstream plug launch indicator, and
 wherein the downstream cage is configured to receive an additional plug and configured to move between an initial position of the downstream cage and a launch position of the downstream cage.   
     
     
         33 . The method of  claim 32 , the method further comprising
 positioning the downstream cage in the initial position of the downstream cage; loading the additional plug into an internal bore of the downstream cage; attaching the downstream cement head body to the cement head body; pumping the fluid through the opening of the cap such that the fluid flows around an outside of the cage and an outside of the downstream cage; and   prior to releasing the cage, releasing the downstream cage such that the downstream cage moves from the initial position of the downstream cage to the launch position of the downstream cage to redirect fluid from flowing around the outside of the downstream cage to flowing through the internal bore of the downstream cage to push the additional plug out of the downstream cage,   wherein the additional plug moves through the downstream cement head body and contacts the downstream plug launch indicator to actuate the downstream plug launch indicator.