System and method for dual tubing well design and analysis cross-reference to related applications

Abstract

Methods and systems for analyzing a well system design including determining a volume change of trapped annular regions based on a plurality of initial temperatures and a plurality of final temperatures and an initial pressure. Analyzing the trapped annular regions to determine an enclosure volume change, a fluid expansion volume, and an annular pressure buildup for a safe well system and generating a graphical representation of the bounds of the safe well system envelop.

What is claimed is: 
     
         1 . A method for designing a well system envelop, the method comprising:
 creating an initial design for a well system including two or more tubing strings disposed within a well, the well system including one or more trapped annular regions therein, each of the one or more trapped annular regions including an enclosure;   determining a plurality of initial temperatures, a plurality of final temperatures, and an initial pressure for each of the one or more trapped annular regions;   estimating a final pressure for each of the one or more trapped annular regions;   analyzing each of the one or more trapped annular regions; and   generating a wellbore system envelop based at least in part on the analysis of each of the one or more trapped annular regions.   
     
     
         2 . The method of  claim 1 , wherein analyzing the one or more trapped annular regions further comprises:
 selecting a first trapped region from the one or more trapped annular regions;   calculating an enclosure volume change for the first trapped region; and   calculating an annular fluid expansion (AFE) of a well fluid contained within the enclosure of the first trapped region, the AFE corresponding to a fluid volume change caused by a temperature change.   
     
     
         3 . The method of  claim 2 , wherein analyzing the one or more trapped annular regions further comprises determining an annular pressure buildup (APB) corresponding to the first trapped region, wherein when the enclosure volume change for the first trapped region is balanced with the AFE for the first trapped region. 
     
     
         4 . The method of  claim 3 , further comprising calculating a plurality of APBs corresponding to each of the plurality of initial temperatures and the plurality of final temperatures. 
     
     
         5 . The method of  claim 4 , wherein when the well system further includes at least two casings the enclosure of the one or more trapped annular regions includes one or more casing enclosures between two casings, one or more casing and tubing enclosures between a casing and a tubing string, and one or more tubing enclosures between two tubing strings. 
     
     
         6 . The method of  claim 4 , further comprising calculating a respective enclosure volume change, a plurality of respective AFEs, and a plurality of respective APBs for each of the remaining one or more trapped annular regions. 
     
     
         7 . The method of  claim 6 , further comprising iterating the calculations of the plurality of respective APBs for each of the one or more trapped annular regions assuming a non-rigid enclosure. 
     
     
         8 . The method of  claim 7 , further comprising determining whether a global pressure of the well system is balanced for each of the one or more trapped annular regions within the well system based on the non-rigid enclosures. 
     
     
         9 . The method of  claim 8 , further comprising:
 generating a graphical representation of the of the wellbore system envelop showing a safe design limit, and   transmitting the graphical representation to an output device.   
     
     
         10 . The method of  claim 1 , wherein the plurality of initial temperatures, the initial pressure, and the plurality of final temperatures for each of the one or more trapped annular regions are determined using calculations and/or simulation. 
     
     
         11 . A non-transitory computer-readable storage medium storing computer-executable instructions which, when executed by one or more processors, cause the one or more processors to:
 create initial design for a well system including two or more tubing strings disposed within a well, the well system including one or more trapped annular regions therein, each of the one or more trapped annular regions including an enclosure;   determine a plurality of initial temperatures, a plurality of final temperatures, and an initial pressure for each of the one or more trapped annular regions;   estimate a final pressure for each of the one or more trapped annular regions;   analyze each of the one or more trapped annular regions; and   generate a wellbore system envelop based at least in part on the analysis of each of the one or more trapped annular regions.   
     
     
         12 . The non-transitory computer-readable storage medium of  claim 11 , wherein the instructions further cause the processor to:
 select a first trapped region from the one or more trapped annular regions;   calculate an enclosure volume change for the first trapped region; and   calculate an annular fluid expansion (AFE) of a well fluid contained within the enclosure of the first trapped region, the AFE corresponding to a fluid volume change caused by a temperature change.   
     
     
         13 . The non-transitory computer-readable storage medium of  claim 12 , wherein the instructions further cause the processor to:
 determine an annular pressure buildup (APB) corresponding to the first trapped region, wherein the enclosure volume change for the first trapped region is balanced with the AFE for the first trapped region.   
     
     
         14 . The non-transitory computer-readable storage medium of  claim 13 , wherein the instructions further cause the processor to:
 calculate a plurality of APBs corresponding to each of the plurality of initial temperatures and the plurality of final temperatures.   
     
     
         15 . The non-transitory computer-readable storage medium of  claim 14 , wherein the instructions further cause the processor to:
 calculate a respective enclosure volume change, a plurality of respective AFEs, and a plurality of respective APBs for each of the remaining one or more trapped annular regions.   
     
     
         16 . The non-transitory computer-readable storage medium of  claim 15 , wherein the instructions further cause the processor to:
 iteratively calculate a plurality of respective APBs for each of the one or more trapped annular regions assuming a non-rigid enclosure.   
     
     
         17 . The non-transitory computer-readable storage medium of  claim 16 , wherein the instructions further cause the processor to:
 determine whether a global pressure of the well system is balanced for each of the one or more trapped annular regions within the well system based on the non-rigid enclosures.   
     
     
         18 . The non-transitory computer-readable storage medium of  claim 17 , wherein when the well system is balanced the instructions further cause the processor to:
 generate a graphical representation of the well system envelop showing a safe design limit; and   display the well system envelop and the safe design limit on an output device communicatively coupled with the one or more processors.   
     
     
         19 . A system comprising:
 a well system including a wellbore having at least two tubing strings and at least one casing disposed therein, the well system including a plurality of trapped annular regions, each of the plurality of trapped annular regions being a non-rigid enclosure;   one or more processors coupled with an input device; and   at least one non-transitory computer-readable storage medium storing instructions which, when executed by the one or more processors, cause the one or more processors to:   receive a plurality of initial temperatures, an initial pressure, and a plurality of final temperatures corresponding to each of the plurality of trapped annular regions from one or more sensors located within the wellbore of the well system;   estimate a final pressure for each of the one or more trapped annular regions;   analyze each of the one or more trapped annular regions; and   generate an integrity report for the well system, wherein the integrity report is based at least in part on the analysis of each of the plurality of trapped annular regions.   
     
     
         20 . The system of  claim 19 , wherein the integrity report includes a temperature range and a pressure range at which the well system will fail.