[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"doc-detail-81798-en":3,"doc-seo-81798-105":29,"detail-sidebar-cat-0-en-105":90},{"code":4,"msg":5,"data":6},0,"success",{"doc_id":7,"user_id":8,"nickname":9,"user_avatar":10,"doc_module":4,"category_id":11,"category_name":12,"doc_title":13,"doc_description":14,"doc_content":15,"file_id":16,"file_url":17,"file_type":18,"file_size":19,"view_count":4,"is_deleted":4,"is_public":20,"is_downloadable":20,"audit_status":20,"page_count":21,"language":22,"language_code":23,"site_id":24,"html_lang":23,"table_of_contents":25,"faqs":26,"seo_title":13,"seo_description":14,"update_tm":27,"read_time":28},81798,137441390410,"Hazel","https://ap-avatar.wpscdn.com/avatar/2000252f4ab5702993?_k=1776741390130283984",8,"Research & Report","Verification of a Sequential Thermo Poroelasticity Formulation in PFLOTRAN","Verification of thermo–hydrologic–mechanical (THM) coupling in PFLOTRAN focuses on benchmark-based assessment of the THM implementation. Thermal–hydrologic mass and energy balance equations are solved on control-volume blocks or Voronoi cells, while quasi-static momentum balance is solved on an element-based dual mesh. Coupling uses a strictly sequential, non-iterative fixed-stress split: implicit pressure/temperature solve followed by mechanics displacement update. Multiple benchmarks confirm agreement for pressure diffusion, temperature fields, and deformation, and a fracture-capable discontinuity treatment is validated against an analytical solution, establishing a modeling foundation for subsurface THM applications.","arXiv :2607 .01156v2 [physics .comp-ph] 3 Jul 2026  \nVerification of a sequential thermo-poroelasticity formulation  \nin PFLOTRAN  \nJ. Al Kubaisy 1*, G. E. Hammond 1 , S. Karra2 , J. Burghardt 1 , L. Murdoch3 ,  \nT. Johnson 1 , K. M. Rosso2  \n1* Energy and Environment Directorate, Pacific Northwest National Laboratory,  \nRichland, 99352, WA, USA.  \n2 Integrated Discovery Sciences Directorate, Pacific Northwest National Laboratory, Richland, 99352, WA, USA.  \n3 Environmental Engineering and Earth Science Department, Clemson University, Clemson, 29634, SC, USA.  \n*Corresponding author(s). E-mail(s): [jumanah.alkubaisy@pnnl.gov](jumanah.alkubaisy@pnnl.gov) ;  \nAbstract  \nWe present the verification of a thermo–hydrologic–mechanical capability implemented within the PFLOTRAN framework, with emphasis on benchmark-based assessment of the THM implementation. The thermal–hydrologic (TH) equations for mass and energy balance are solved on control-volume blocks or Voronoi cells, while the quasi-static momentum balance is solved on an element-based dual mesh. The coupling is achieved using a strictly sequential, non-iterative fixedstress split strategy in which the TH system is solved implicitly for pressure and temperature, followed by a mechanics update for the displacement unknowns. Several verification problems are set up against poroelastic and thermo-poroelastic benchmarks, demonstrating agreement with analytical or semi-analytical benchmark responses for pressure diffusion, the temperature field, and mechanical deformation. In addition, we propose a treatment for discontinuities (e.g., fractures) based on mapping between mechanical and flow degrees of freedom, and validate the approach by comparison to an analytical solution. This work establishes the basis for thermo–poroelastic coupling in PFLOTRAN and provides a solid modeling foundation for a range of applications (e.g., enhanced geothermal systems and other subsurface energy storage) involving coupled thermal–hydrologic–mechanical (THM) processes in geologic porous media.  \nKeywords: Thermo-hydrologic-mechanical, coupled processes, flow, mechanics, PFLOTRAN, subsurface, geothermal  \n1 Introduction  \nCoupled thermal–hydrologic–mechanical (THM) processes in geological porous media govern the evolution of pressure, temperature, stress, and deformation across a wide range of subsurface applications, including underground energy storage [1], carbon sequestration [2], and geothermal energy systems [3] . In such systems, pore pressure changes can impact mechanical stresses resulting in compaction, stress redistribution, and fracture opening and closure [4–6] . Temperature variations introduce thermoelastic effects and can strongly affect fluid and rock properties, with corresponding impacts on flow and pressure diffusion [7, 8] . In many settings, geochemical coupling through thermo–hydrologic–mechanical–chemical (THMC) processes introduces additional feedback via fluid–rock interactions (e.g., dissolution–precipitation and mineral alteration) . These reactions can alter  \nporosity and permeability [9, 10] and may also affect mechanical strength and stiffness, thereby influencing flow, heat transport, and deformation. Capturing these dynamics is important for understanding and assessing performance in engineered subsurface operations and natural hydrothermal environments.  \nRobust numerical approximations of THM coupled processes remain challenging because they combine nonlinear flow and heat transport with mechanical deformation over highly heterogeneous media and multiple spatial and temporal scales. Monolithic formulations where a single system of equations is set up to solve all primary unknowns simultaneously can offer strong coupling but may be complex to implement and computationally demanding–particularly for large three-dimensional problems– while sequential (or operator-splitting) strategies improve modularity but must be designed to preserve stability and accuracy [8, 11]","cbCain3rUeTobnhq","https://ap.wps.com/l/cbCain3rUeTobnhq","pdf",3714844,1,22,"English","en",105,"# Abstract\n# Introduction\n## THM coupling in geological porous media\n## Numerical challenges and operator-splitting approaches\n## Fixed-stress vs. undrained splits\n## Open-source codes and motivation for PFLOTRAN\n## PFLOTRAN capabilities and geomechanics background","[{\"question\":\"What is being verified in this work on PFLOTRAN?\",\"answer\":\"The work verifies a thermo–hydrologic–mechanical (THM) capability implemented within PFLOTRAN, emphasizing benchmark-based assessment of the THM coupling implementation.\"},{\"question\":\"How are the thermal–hydrologic and mechanical equations discretized and solved?\",\"answer\":\"Thermal–hydrologic (mass and energy balance) equations are solved on control-volume blocks or Voronoi cells, while the quasi-static momentum balance is solved on an element-based dual mesh.\"},{\"question\":\"What coupling strategy links the TH and mechanics subproblems?\",\"answer\":\"A strictly sequential, non-iterative fixed-stress split is used: the TH system is solved implicitly for pressure and temperature, then a mechanics update computes displacement unknowns.\"}]",1784176227,55,{"code":4,"msg":30,"data":31},"ok",{"site_id":24,"language":23,"slug":32,"title":13,"keywords":33,"description":14,"schema_data":34,"social_meta":85,"head_meta":87,"extra_data":89,"updated_unix":27},"verification-of-a-sequential-thermo-poroelasticity-formulation-in-pflotran","",{"@graph":35,"@context":84},[36,53,67],{"@type":37,"itemListElement":38},"BreadcrumbList",[39,43,47,50],{"item":40,"name":41,"@type":42,"position":20},"https://docshare.wps.com","Home","ListItem",{"item":44,"name":45,"@type":42,"position":46},"https://docshare.wps.com/document/","Document",2,{"item":48,"name":12,"@type":42,"position":49},"https://docshare.wps.com/document/research-report/",3,{"item":51,"name":13,"@type":42,"position":52},"https://docshare.wps.com/document/verification-of-a-sequential-thermo-poroelasticity-formulation-in-pflotran/81798/",4,{"url":51,"name":13,"@type":54,"author":55,"headline":13,"publisher":57,"fileFormat":60,"inLanguage":23,"description":14,"dateModified":61,"datePublished":61,"encodingFormat":60,"isAccessibleForFree":62,"interactionStatistic":63},"DigitalDocument",{"name":9,"@type":56},"Person",{"url":40,"name":58,"@type":59},"DocShare","Organization","application/pdf","2026-07-16",true,{"@type":64,"interactionType":65,"userInteractionCount":4},"InteractionCounter",{"@type":66},"ViewAction",{"@type":68,"mainEntity":69},"FAQPage",[70,76,80],{"name":71,"@type":72,"acceptedAnswer":73},"What is being verified in this work on PFLOTRAN?","Question",{"text":74,"@type":75},"The work verifies a thermo–hydrologic–mechanical (THM) capability implemented within PFLOTRAN, emphasizing benchmark-based assessment of the THM coupling implementation.","Answer",{"name":77,"@type":72,"acceptedAnswer":78},"How are the thermal–hydrologic and mechanical equations discretized and solved?",{"text":79,"@type":75},"Thermal–hydrologic (mass and energy balance) equations are solved on control-volume blocks or Voronoi cells, while the quasi-static momentum balance is solved on an element-based dual mesh.",{"name":81,"@type":72,"acceptedAnswer":82},"What coupling strategy links the TH and mechanics subproblems?",{"text":83,"@type":75},"A strictly sequential, non-iterative fixed-stress split is used: the TH system is solved implicitly for pressure and temperature, then a mechanics update computes displacement 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