连续管钻井低扭矩钻头破岩机制及仿真

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中图分类号：TE921 文献标志码：A

Abstract：Inthis study，inorder toadressthe issuesoflimited weight-on-bit（WOB）andshallowpenetrationdepth in coiledtubing drilling，adesignofalow torqueonbit（TOB）PDCrock-breakingdrillbit forcoiledtubing was proposed.TheoreticalanalysesofcuttingforceratioofPDCcutters，andcuttngforcedistributionpaternofdiferentcuters，inludingconventionalcutter，chord-edge-cutter，and bluntanglecutter，werecarriedout，andsingle-cutter straight-linecuttingrockbreaking experiments wereconducted to investigatethe impactof diferentcuterdiameters andshapes onthecuting force.A full-scale PDCdrillbit-rock interactionmodel wasdeveloped tostudytherock-breakingperformanceofconventionalcuter， chord-edge-cutter，andblunt anglecutterdrillbits，which wasvalidatedthrough full-scalerock-breaking experiments.The resultsshowthatchord-edge-cuterand bluntangle cuter exhibit beterpenetrationperformanceandhavesignificantly more uniform cutting force compared to the conventional cutters，with 14.11% to 33.59% of cutting forces reduction. The errors of the simulation results using the established full-scale drill bit rock-breaking model are less than 15% compared to the experimentalresults，demonstrating a high accuracyof the model.Under thesame RPMand WOB，blunt anglecuterPDCdrillbits exhibit the best TOB reduction effect，with a maximum TOB reduction of 35.35% .It is recommended that blunt angle cutter PDCdrillbitsaremoresuitableforthelow TOBrock-breaking incoiledtubingdrillngthan theconventionalcuterbits.

Keywords：coiled tubing driling；low TOB；specific pressure；blunt angle cutter；rock-breaking simulation

中国油气行业的基本现状为多井低产、非常规油气逐渐成为油气上产的主体[1-2]，连续管以其钻柱连续、带压作业、不间断循环和适合欠平衡钻井等优势受到广泛应用，在修井、测井、完井等领域逐渐成为传统钻井作业的经济替代品[3-6]。（剩余14116字）