Drilling Technology of HTHP Ultradeep Well and the Crucial Technique Application

Abstract There are many difficulties in HTHP ultradeep well drilling, drilling technology of HTHP ultradeep well is still the focal point of drilling researching and developing at present. This paper introduce drilling technology of HTHP ultradeep well moshen-1 well. Specially, this paper give information of the crucial technique application in Xinjiang Karamay Oilfield. Moshen-1 well is an important exploration well of CNPC, the designed well depth was 7380m, the actually completed well depth 7500m. Drilling engineering encountered huge challenges for instance high bottom hole temperature and high formation pressure coefficient, no reference data below depth 5300m. By optimizing drilling design, the construction of every drilling section was successfully finished. By optimizing BHA and using Power-V vertical drilling system, combine a large-sized PDM with PDC bit, using turbodrilling, all helped controlling wellbore quality effectively. By optimizing bit design and PDC bit selection increased drilling bit footage. Specially, 35MPa high pressure jet drilling technique had effectively increased bit hydraulic horsepower and improved the drilling ROP, reduced drilling cycle, achieved success contrast with neighboring well. The success of Moshen-1 well drilling and the application of high pressure jet drilling technique provide valuable experience for other ultradeep wells drilling and for other wells ROP enhancement.