The Key to Successfully Applying Today's Lost Circulation Solutions

Abstract

The Key to Successfully Applying Today's Lost Circulation Solutions Hong Wang; Hong Wang Halliburton Co. Search for other works by this author on: This Site Google Scholar Ronald Earl Sweatman; Ronald Earl Sweatman Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Robert E. Engelman; Robert E. Engelman Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Wolfgang F.J. Deeg; Wolfgang F.J. Deeg Shell Search for other works by this author on: This Site Google Scholar Donald L. Whitfill Donald L. Whitfill Halliburton Energy Services Group Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, October 2005. Paper Number: SPE-95895-MS https://doi.org/10.2118/95895-MS Published: October 09 2005 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Wang, Hong, Sweatman, Ronald Earl, Engelman, Robert E., Deeg, Wolfgang F.J., and Donald L. Whitfill. "The Key to Successfully Applying Today's Lost Circulation Solutions." Paper presented at the SPE Annual Technical Conference and Exhibition, Dallas, Texas, October 2005. doi: https://doi.org/10.2118/95895-MS Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll ProceedingsSociety of Petroleum Engineers (SPE)SPE Annual Technical Conference and Exhibition Search Advanced Search AbstractThough strengthening boreholes with particulate treated mud has achieved tremendous success in the past year, the theory behind the process still has not been widely accepted. Rock mechanics analysis and laboratory data review are performed in this paper to illustrate deepened understanding on some key points that are controversial. Algorithms have been developed and demonstrated for obtaining critical parameters in designing such jobs for improving hoop stress, by which a wellbore can be strengthened while drilling.Discussion of mechanisms and case histories has led to the development of systems that are designed to improve wellbore-pressure containment (WPC) by improving least principal stress. These systems are designed to function independent of formation permeability, unlike high fluid-loss and high solid-content squeeze pills. This method is normally applied when long fractures exist and when lost circulation has occurred.Since the first approach is proactive and the latter remedial or corrective, combining the two approaches can create synergy for borehole strengthening.A computer-aided design (CAD) process is also demonstrated for better use of available information in designing a deformable, viscous, and cohesive (DVC) system.IntroductionDuring the last century, lost circulation (LC) has presented great challenges to the petroleum industry, causing great expenditures of cash and time to fighting the problem. Trouble costs for mud losses, wasted rig time, ineffective remediation materials and techniques, and in the worst cases—for lost holes, sidetracks, bypassed reserves, abandoned wells, relief wells, and lost petroleum reserves have continued into this century. The risk of drilling wells in areas known to contain these problematic formations is a key factor in decisions to approve or cancel exploration and development projects.Background literature[1] on the subject describes many methods and materials used to remedy LC. Many of these methods have worked in some wells but not in others. Trial and error applications almost always resulted in a costly learning curve. Some worst-case wells had to be drilled "blind" or with a "mud cap" to minimize losses.An API study published in 1991 includes data[2] (Table 1) indicating that up to 45% of all wells require an intermediate casing string to prevent severe LC while drilling to total depth (TD). Even when using these extra strings, LC events still occurred in 18 to 26% of all hole sections. Some areas reported many more occurrences of LC events ranging from 40% to 80% of wells. In recent years, these percentages have likely increased as the number of shallow, easy-to-find reservoirs has steadily declined and industry operators have intensified their search for deeper reservoirs and drilled through depleted or partially depleted formations. Conventional lost-circulation materials (LCM) including pills, squeezes, pretreatments, and drilling procedures employing equivalent circulating density (ECD) management often reach their limit in effectiveness and become unsuccessful in the deeper hole conditions where some formations are depleted, structurally weak, or naturally fractured and faulted.With continued drilling of deepwater wells, HPHT wells, infill wells, etc., the mud-weight window (MWW) is not only becoming much narrower, but also more uncertain. To address these issues, new LC solutions and concepts such as borehole strengthening or WPC have been evolving. The mechanics behind various means proposed and used to enhance WPC are still being debated and are not fully understood. Proposed mechanisms include sealing incipient fractures at the wellbore wall; propping open multiple short fractures at the wellbore wall, thus increasing compressive stresses around wellbore; and sealing fractures with various materials using hesitation-squeeze technology. Our understanding of current prevailing practice could be greatly enhanced if data required to perform rock mechanics analyses were available in a timely manner, allowing us to understand downhole conditions and translate this data into usable knowledge for drilling. Keywords: wellbore pressure, spe 95895, breakdown pressure, log analysis, wellbore integrity, borehole, information, incipient fracture, upstream oil & gas, principal stress Subjects: Wellbore Design, Pressure Management, Drilling Fluids and Materials, Hydraulic Fracturing, Reservoir Characterization, Formation Evaluation & Management, Wellbore integrity, Well control, Drilling fluid selection and formulation (chemistry, properties), Drilling fluid management & disposal This content is only available via PDF. 2005. Society of Petroleum Engineers You can access this article if you purchase or spend a download.