WH Wellbore Solutions
Independent Consulting
Houston, TX
ABOUT
Dr. Wenwu He is an independent consultant. He was the Formation Damage & Stability Manager at SLB Well Construction Fluids where he managed the Formation Damage & Stability group for 15 years, from 2009 to 2024. This group is the primary laboratory for formation damage and fluid-induced wellbore stability within SLB and serves SLB’s global operations. Dr. He became a SLB Technical Advisor (SETC advisor) in January 2018 and served as the leading and only advisor-level expert in the entire organization on formation damage and fluid-induced wellbore stability. He collaborated with every major O&G company and has experience with a wealth of drilling and completion conditions and formation types.
Dr. He has a comprehensive educational background including a Ph.D. degree in geochemistry from China University of Geosciences and a Ph.D. degree in geology from Texas A&M University. He was a faculty member at China University of Geosciences for 7 years where he taught several undergraduate and graduate courses. Dr. He has published extensively in well regarded, peer-reviewed scientific journals and published papers and presented at SPE, IADC, IPTC, AADE, URTeC, AAPG, and AGU conferences. In addition to his extensive experience in theoretical and numerical modeling, Dr. He is well versed in designing and conducting laboratory experiments on rock mechanics, formation damage, HTHP fluid-rock interactions, and shale stability. He is proficient with equipment used for studying formation damage, fluid-rock interactions, shale stability, and rock mechanics in both industry and academic institutions.
Formation damage is a major concern in drilling reservoir formations while wellbore stability is a top issue in drilling shale formations. Both formation damage and wellbore instability present an undesirable effect operationally and economically. Dr. He’s education background, extensive experience in theoretical studies, laboratory analyses and experiments, practical applications, and deep understanding in drilling and completion fluids allow him to explore formation damage and wellbore stability from different perspectives including laboratory investigation vs practical application, analyses at macro- vs micro-scales, and mechanical vs chemical processes. Dr. He has become recognized in the O&G industry as a leading investigator of formation damage by drilling and completion fluids, shale–fluid interactions and wellbore stability.
SERVICES
Design of drilling and completion fluids: optimal performance by minimizing formation damage and preventing wellbore instability Beyond maintaining appropriate rheology profile and thermal stability, this includes: 1. Bridging particle size distribution optimized for formation rocks 2. Selection of chemical inhibitors for clay minerals 3. Prevention of emulsion and other incompatibility of fluid phases (e.g., filtrate, formation water, and production fluid/oil) 4. Compatibility of internal phase salinity with the water activity of drilled shale formation (for oil-based fluid)
Formation evaluation: petrographic investigation (thin section, SEM, etc.), analytical analysis (XRD, RCA, mercury injection, etc.), rock mechanics and petrophysics studies Understanding the formation properties is the foundation of designing a low-damage fluid. The properties include: 1. Mineral composition including clay minerals, rock structure and texture, bedding planes and lamination 2. Porosity/permeability, pore size distribution and connectivity, fractures 3. Relative permeability, water block, wettability 4. Formation fluid composition and water activity 5. Rock strength, compaction and deformation properties
Evaluation of formation damage for oil, gas and geothermal production: mechanisms, minimization, and mitigation It is essential to understand the formation damage mechanisms in order to minimize and mitigate the damages. Formation damage mechanisms are complicated, but by understanding formation rocks, analyzing field data, tailoring laboratory testing, conducting microstructural study of post-testing samples, and properly interpreting data, the damage mechanisms can be identified and solutions to minimize or mitigate the damage can be implemented.
Analysis of wellbore instability: causes, mechanisms, controlling factors, and prevention Drilling in shale formations is fraught with the challenge of wellbore instability, which is caused by mechanical and chemical interactions between drilling fluids and shale formations. Experimental investigation can identify these complex mechanisms, such as capillary, swelling, dispersion, fracturing, osmosis, pressure transmission, etc., and the complex factors that contribute to wellbore instability. Shales are characterized by complex mineralogy, structure, bedding, and laminations. Thus, evaluation of pre- and post-testing samples is essential to identifying the causes and mechanisms of shale failure.
Quantitative evaluation of filtrate invasion depth and velocity: wellbore invasion modeling constrained by drilling fluid core testing Invasion of drilling fluid filtrate into formation is a primary cause for formation damage which results in the reduction of productivity of oil and gas. It can also lead to inaccurate and inconsistent well log measurements. Wellbore invasion modeling constrained by drilling fluid core testing results provides a tool to quantitatively characterize the depth and velocity of filtrate invasion into wellbore formation.
Exploration of fluid invasion and movement in shale formation: capillary, osmosis, hydration and dehydration, and pore-pressure transmission Fluid invasion and movement in near-wellbore shale formation is a major mechanism for wellbore failure. Water fluxing into or out of shale formation can greatly change the stress status, alter the mechanical and chemical properties of shale and destabilize the wellbore. Proper design and execution of experiments (e.g., pore pressure transmission testing) and detailed microstructural studies of post-tested samples can help understand the invasion and movement of fluids in shale, including mechanisms, affecting factors, and the impact of fluid invasion and movement on wellbore stability.
Case-specific formation damage testing: method/procedure design and data interpretation Designing proper testing methods and procedures is essential to evaluate the damage potential and mechanisms. By designing case-specific testing procedures, different damage factors, such as external and internal filter cakes, filtration, near wellbore invasion, fines migration, etc., can be identified and quantified. Incompatibility between liquid phases such as emulsion, precipitation etc., can be characterized with careful laboratory testing/analyses. Selection of appropriate aloxite disk with similar pore size distribution to the drilled formation is critical to achieving accurate results in fluid optimization.
Case-specific shale-fluid interaction testing: method/procedure design and data interpretation The physical, chemical, mineralogical, and structural features of shale require special considerations for shipping, handling, cleaning, and preparing the samples for testing. Changes in microstructure and hydration status due to improper handling can dramatically alter shale properties and improperly skew results. Each testing program should be tailored to the specific drilling issues and challenges, sample availability, quality and quantity. Post-testing sample investigation can further characterize the structural and mineralogical change induced by shale-fluid interaction.
Personalized courses:
-
Formation Damage: Mechanisms & Mitigation
-
Mechanical and Chemical Wellbore Stability
-
Rock-Fluid Interactions and Drilling/Completion Application
-
Bridging Particle Design for Reservoir Drilling-In Fluids and Drilling Fluids
-
Reservoir Drill-In Fluids Design