Cementing method allowing initial liner top pressure integrity confirmation

Abstract

Cementing takes place after a hanger and seal are set to first insure the pressure integrity of the connection between the string to be cemented and the existing tubular. Cementing top down or bottom up is envisioned with either displaced fluid returning toward the surface in a crossover tool or with the displaced fluid squeezed into the formation. A work string manipulates the crossover for reversing out after cementing. For running in a valve assembly is held open to permit circulation. Work string manipulation allows at least one valve that keeps the cement in the annulus to close and at least one other valve to close that keeps the reverse fluid from leaving the cemented tubular to allow such flow to return to the crossover and out to the surface. Valve release can be done with a pressure responsive sleeve instead of a stinger on the running string.

1 . A well completion method for supporting and cementing a tubular string from an existing tubular, said method comprising the steps of:
 running in, on a running string, said tubular string with a hanger and seal assembly to position said hanger and seal assembly by the desired location on the existing tubular;   setting the hanger and seal;   pressure testing the integrity of the connection between the string and the existing tubular after said setting; and   cementing said tubular string after said setting and said pressure testing.   
     
     
         2 . The method of  claim 1 , further comprising the step of:
 performing said cementing of said tubular string top down.   
     
     
         3 . The method of  claim 2 , further comprising the step of:
 allowing fluid displaced by said cementing into the tubular string.   
     
     
         4 . The method of  claim 2 , further comprising the step of:
 squeezing fluid displaced by said cementing of said tubular string into a surrounding geological formation.   
     
     
         5 . The method of  claim 1 , further comprising the step of:
 performing said cementing of said tubular string bottom up.   
     
     
         6 . The method of  claim 1 , further comprising the step of:
 circulating fluid through said tubular running string and said tubular string when running in, through a plurality of open valves located near a lower end of the tubular string.   
     
     
         7 . The method of  claim 6 , further comprising the step of:
 initially holding open said valves for circulating fluid.   
     
     
         8 . The method of  claim 6 , further comprising the step of:
 providing at least one of said valves as a selectively operable first check valve allowing flow into said lower end of said tubular string when operable and another of said valves as a selectively operable second one way valve preventing flow into said tubular string when operable.   
     
     
         9 . The method of  claim 8 , further comprising the step of:
 locating said second check valve closer to a surface location than said first check valve.   
     
     
         10 . The method of  claim 9 , further comprising the step of:
 making said first and second check valves flapper valves.   
     
     
         11 . The method of  claim 10 , further comprising the steps of:
 holding said first flapper valve open with a stinger connected to a running string; and   allowing said flapper valve to operate by raising said stinger with a running string.   
     
     
         12 . The method of  claim 10 , further comprising the steps of:
 holding said second flapper valve open with a second flapper sliding sleeve and   using applied pressure in the tubular string to shift said second flapper sliding sleeve to enable said second flapper to operate.   
     
     
         13 . The method of  claim 10 , further comprising the steps of:
 holding said second flapper open with a sliding sleeve; and   using applied pressure in the tubular string to shift said sleeve to enable said another flapper valve associated with said sleeve to operate.   
     
     
         14 . The method of  claim 12 , further comprising the step of:
 performing said raising of said stinger after said fluid circulating and before said reverse cementing circulation.   
     
     
         15 . The method of  claim 14 , further comprising the step of:
 performing shifting said sliding sleeve after said cementing to enable said second flapper valve to keep cement in a surrounding annulus.   
     
     
         16 . The method of  claim 15 , further comprising the step of:
 using said first flapper valve to redirect reversing flow in said tubular string to take out excess cement.   
     
     
         17 . The method of  claim 16 , further comprising the step of:
 using a crossover tool in said running string; and   directing reversing out excess cement flow to outside said running string at said crossover tool and taking returns with the excess cement through said crossover tool and out to a surface location via an annular space between said running string and said tubular string.   
     
     
         18 . The method of  claim 17 , further comprising the step of:
 providing redundant first or second flapper valves.   
     
     
         19 . The method of  claim 12 , further comprising the steps of:
 holding said first flapper valve open with a first flapper sliding sleeve; and   using applied pressure in the tubular string to shift said first flapper sliding sleeve to enable said first flapper valve to operate.   
     
     
         20 . The method of  claim 19 , further comprising the step of:
 moving said first flapper sliding sleeve before said second flapper sliding sleeve.   
     
     
         21 . The method of  claim 20 , further comprising the steps of:
 cementing after moving said first sliding sleeve; and   using said first flapper valve when made operable by said moving said first flapper sliding sleeve to allow fluid displaced by cement to enter said tubular string.   
     
     
         22 . The method of  claim 21 , further comprising the steps of:
 moving said second flapper valve sliding sleeve after delivering the cement; and   using said second flapper valve made operable by moving said second flapper sliding sleeve to prevent cement in the annular space around said tubular string from entering the tubular string.   
     
     
         23 . The method of  claim 21 , further comprising the steps of:
 deflecting open said second flapper valve with reverse flow into said tubular string from a surface location after said cementing; and   redirecting said reverse flow in said tubular string with said first flapper valve to remove excess cement toward a surface location.   
     
     
         24 . The method of  claim 19 , further comprising the steps of:
 providing a selectively operable seal in an annular space between said running string and said tubular string; and   positioning said seal in a sealing position and blocking said running string adjacent said seal to retain cement in the surrounding annulus should said second flapper valve fail to operate.   
     
     
         25 . A petroleum well liner cementing assembly comprising:
 a drill pipe string with a tubular string release tool arranged for holding a liner hanger setting sleeve of a liner string;   said liner string provided with a liner hanger and seal assembly;   said liner string provided with an annulus cementing port operated by a crossover tool assembly arranged on said drill pipe string below said tubular string release tool;   said liner string provided with lover valves held open during running in by a cementing stinger arranged below said crossover tool assembly; and   said seal assembly allowing pressure testing when said liner hanger is set in a casing.   
     
     
         26 . The liner cementing assembly of  claim 25 , said crossover tool assembly arranged for shifting a cementing section's valve sleeve to open cementing ports while said cementing stinger is shifted upwards out of said lover valves, allowing reverse circulating in of cement from said cement ports to the liner annulus and back through said lower valves of said liner string. 
     
     
         27 . The liner cementing assembly of  claim 26 , said valves arranged for being shut after reverse circulating in of cement, so as for allowing normal circulation washing out of excess cement within said liner below said crossover tool having shut said cement ports. 
     
     
         28 . The liner cementing assembly of  claim 26 , said running string arranged for normal circulating down of cement above said crossover tool assembly. 
     
     
         29 . The liner cementing assembly of  claim 27 , the running string arranged for reverse circulating down the running string's annulus within the existing tubing and set liner during excess cement wash-out.