Drilling technology of Well Ejiandi-4 for shale gas geological survey in western Hubei

Abstract:

In order to find out the stratigraphic sequence and geological parameters in the shale gas exploration area in western Hubei and reveal the characteristics of stratigraphic oil and gas potential， China Geological Survey has deployed a large-diameter shale gas geological survey Well Ejandi-4 in Jianshi， Hubei province， with a drilling depth of 2026 m. In view of drilling challenges， such cementing difficulties， e.g. gravel layer， confined water layer and dipped formation， collapse and falling stones， with proper selection of the drilling bit， optimization of the drilling string， and development of the high-efficiency drilling fluid system， a drilling process combining quick drilling and deviation prevention for gravel layers has been formed. For the coexistence of overflow and leakage， detailed technical measures have been prepared from the aspects of wellbore drifting ， casing running and cementation， and the target of “wearing shoes and hats” has been realized. The drilling technology of Well Ejandi-4 can provide useful experience for future oil and gas drilling in western Hubei.