Innovative Concentric Reamer Enhances Deepwater Drilling Operations

Abstract

Innovative Concentric Reamer Enhances Deepwater Drilling Operations Gregory C. Miller; Gregory C. Miller Smith Services Smith International Inc. Search for other works by this author on: This Site Google Scholar Ronald D. Childers Ronald D. Childers Smith Services Smith International Inc. Search for other works by this author on: This Site Google Scholar Paper presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, October 2003. Paper Number: SPE-84247-MS https://doi.org/10.2118/84247-MS Published: October 05 2003 Cite View This Citation Add to Citation Manager Share Icon Share Twitter LinkedIn Get Permissions Search Site Citation Miller, Gregory C., and Ronald D. Childers. "Innovative Concentric Reamer Enhances Deepwater Drilling Operations." Paper presented at the SPE Annual Technical Conference and Exhibition, Denver, Colorado, October 2003. doi: https://doi.org/10.2118/84247-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 AbstractA prevailing challenge in today's deepwater drilling arena is to have a reliable and cost-effective system able to simultaneously drill and enlarge a borehole for accommodating multiple casing string programs. This paper presents an innovative practice that advances hole enlargement capabilities and offers a cost-effective solution to wellbore enlargement in deepwater wellbores. The key component is the concentric reamer that is compatible with all rotary steerable and directional drilling systems. The design of this concentric reamer addresses known technical challenges and minimizes performance risks associated with using hole enlarging devices.This paper profiles the development and testing, from concept to field-proofing, of a new tool for deepwater Gulf of Mexico applications in various lithologies and drilling scenarios.IntroductionRunning and cementing casing strings in today's economic environment is very challenging. Typical well design begins with devising the necessary completion system to deliver an economical flow rate and moves up hole with the design of the deepwater casing and drilling programs. Traditional clearance casing applications are being replaced with limited clearance programs. These programs allow for larger production tubing and smaller casing sizes that reduce associated drilling and equipment costs1.Recent technology advances have prompted significant developments in simultaneous drilling and underreaming equipment2. Underreaming, or borehole enlargement, is now a planned process with the minimum clearance multiple string casing programs run today. Borehole enlargement is no longer viewed as only the undesirable yet inevitable solution to problems associated with unstable formations3. Today's robust underreaming tools can reliably cut longer intervals and harder formations at faster penetration rates than previous technology4. However, a perception still exists that there are inherent mechanical problems with underreamers. This perception initiated the market entry and led to the technical developments of bi-center drill bits, reamer wing type tools and the expandable blade hole enlarging devices. Regardless of these developments, tool dependability, vibration and borehole quality remain key concerns with these devices.The concentric reamer described in this paper is designed as an alternative to existing expandable-blade hole enlarging devices, reamer wing tools and fixed-bladed tools such as bi-center bits.Design of the Concentric ReamerThe concentric reamer is a hydraulically expandable reaming tool designed to enlarge a wellbore about 20 percent for improved casing running and cementing clearance. The concentric reamer houses three equally spaced cutter blocks dressed with PDC (polycrystalline diamond compact) inserts for both drilling and backreaming and a unique deployment mechanism.5 See Figure 1.Concentric Hole EnlargementThe cutter blocks extend simultaneously from the tool body to enlarge a concentric, full gauge wellbore below a restriction such as a cased hole. The balanced mass design reduces lateral vibrations detrimental to sensory instrumentation in the bottom hole assembly (BHA). See Figure 2.High Fluid Flow CapabilityThe large internal diameter of the tool allows for the optimum flow rates necessary to adequately clean the enlarged hole section and for the flow requirements of rotary steerable systems (RSS) and directional assemblies. The concentric reamer's jet nozzles travel with the cutter blocks to all the opening diameters. The fluid flow distribution to the bit and cutter blocks can be optimized as directed by hydraulics analysis software for improved hole cleaning. The large bore facilitates the passage of wireline conveyed equipment. See Figure 3. Keywords: reamer, shale, series concentric reamer, concentric reamer, shoe track, steerable system, assembly, bha, case history, torque Subjects: Drilling Operations, Drilling Equipment This content is only available via PDF. 2003. 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