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The optimization of pressure controller for deep earth drilling

ABSTRACT
Obtaining samples of deep in-situ conditions is first step to explore the mysteries of the earth requires .In view of the current problems of insufficient pressure maintaining capacity of the existing equipment, we independently developed the in-situ fidelity coring system and designed the osmotic pressure controller based on the geometry of square cover. The finite element method is used to analyze the pressure maintaining capacity of the pressure controller. It is found that it would produce large deformation and stress concentration when the pressure was applied on, resulting in low pressure maintaining capacity. Then the structural optimization schemes of conical sealing contact surfaces with 25, 35, 40 and 45 degrees apex angles and spherical sealing contact surface are proposed, and the spherical contact surface structure is found to be optimal. Finally, the material is optimized, and a higher strength material such as 45CrNiMoVA alloy is used. Based on the pressure controller with spherical contact surface, the pressure maintaining capacity increased to nearly 70 MPa. The research results obtained in this paper provide the basis for the development of the coring system, the deep exploration of the earth and the establishment of rock mechanics theory.
KEYWORDS
PAPER SUBMITTED: 2018-06-12
PAPER REVISED: 2018-07-11
PAPER ACCEPTED: 2018-12-18
PUBLISHED ONLINE: 2019-04-14
DOI REFERENCE: https://doi.org/10.2298/TSCI180612123H
REFERENCES
  1. Xie H.P., et al., Research and Development of Rock Mechanics in Deep Ground Engineering,Chinese Journal of Rock Mechanics and Engineering,34(2015), 11,pp. 2161-2178
  2. Xie H.P., et al., Quantitative Definition and Investigation of Deep Mining,Journal of China Coal Society, 40(2015), 1,pp. 1-10
  3. Xie H.P.,Research Framework and Anticipated Results of Deep Rock Mechanics and Mining Theory.Advanced Engineering Sciences,49(2017), 2, pp. 1-16
  4. Gao, M., et al., Field Experiments on Fracture Evolution and Correlations Between Connectivity and Abutment Pressure under Top Coal Caving Conditions,International Journal of Rock Mechanics and Mining Science, 111(2018), Oct,pp. 84-93.
  5. Coney L.,et al., Geochemistry of Impactites and Basement Lithologies from ICDP Borehole LB‐07A, Bosumtwi Impact Structure, Ghana,Meteoritics & Planetary Science,42(2007), 4-5,pp. 667-688
  6. Dickens G.R., et al., The Pressure Core Sampler (PCS) on ODP Leg 201: General Operations and Gas Release. Proceedings, The Ocean Drilling Program, Texas A&M University, Texas, US, 2003, Vol. 201
  7. Litt T.,et al., 'PALEOVAN', International Continental Scientific Drilling Program (ICDP): Site Survey Results and Perspectives, Quaternary Science Reviews, 28(2009), 15, pp. 1555-1567
  8. Yun T.S.,Mechanical and Thermal Study of Hydrate Bearing Sediments,Ph. D. Thesis, Georgia Institute of Technology, Georgia, US,2005
  9. Friðleifsson G.Ó., et al., The Iceland Deep Drilling Project 4.5 Km Deep Well, IDDP-2, inthe Seawater-Recharged Reykjanes Geothermal Field inSW IcelandHas Successfully Reached Its Supercritical Target, Scientific Drilling, 23 (2017), 5, pp.1-12
  10. Yun T.S., et al., Hydrate-Bearing Sediments from the Krishna− Godavari Basin: Physical Characterization, Pressure Core Testing, and Scaled Production Monitoring,Energy & Fuels,24(2010), 11, pp. 5972-5983
  11. Wang W.S.,et al., Key Technology of Coring in Hard Rocks for Scientific Ultra-Deep Drilling, Exploration Engineering (Rock & Soil Drilling and Tunneling). 41(2014), 1, pp. 9-12
  12. Rothwell R.G., Rack F.R.,New Techniques in Sediment Core Analysis: an Introduction, Geological Society, London, Special Publications,267( 2006), 1, pp. 1-29
  13. Schultheiss P.,et al., Wireline Coring and Analysis under Pressure: Recent Use and Future Developments ofthe HYACINTH System, Scientific Drilling, 7(2009),Mar, pp. 44-50
  14. Wakishima R.. The Development ofaPressure Temperature Core Sampler (PTCS) forthe Recovery ofIn-Situ Methane Hydrates, Proceedings,The International Symposium on Methane Hydrates, JNOC-TRC, Tokyo,Japan, 1998, Vol. 107
  15. Bohrmann G., et al., Appearance and Preservation of Natural Gas Hydrate From Hydrate Ridge Sampled During ODP Leg 204 Drilling, Marine Geology, 244 (2007), 1, pp. 1-14
  16. Hohnberg H.J.,et al., Pressurized Coring of Near-Surface Gas-Hydrate Sediments on Hydrate Ridge: the Multiple Autoclave Corer, and First Results from Pressure-Core X-Ray CT Scans,Proceedings, EGS -AGU - EUG Joint Assembly ,Nice, France, 2003, Vol. 5
  17. Qin H.W., et al., Pressure Tight Piston Corer-aNew Approach on Gas Hydrate Investigation,China Ocean Engineering,19(2005), 1, pp. 121-128
  18. ChenY., et al., Research onPressure Tight Sampling Technique ofDeep-Sea Shallow Sediment-a New Approach to Gas Hydrate Investigation, China Ocean Engineering,20 (2006), 4, pp. 657-664
  19. Li S.L.,et al., Development of Pressure Piston Corer for Exploring Natural Gas Hydrates, Journal of Zhejiang University(Engineering Science),40(2006),5,pp. 888-892