Safe and efficient wiper trip technology in shallow soft formation of Chenghai 1-1 oilfield block
In the horizontal well drilling on the Chenghai 1-1(CH1-1)Block,the formations drilled were mainly soft sandstone strata of the Minghuazhen Formation and Guantao Formation.Creep closure is likely to occur at the wellbore.Meanwhile,factors including double-increase three-dimensional trajectory and large displacement resulted in a high operation risk of second-spud 311.15 mm wellbore drifting and a new hole was likely to appear.By designing a wiper trip pilot bit,optimizing the wiper trip drilling string and technical measures of the wiper trip,safe and efficient drifting technology was achieved for the shallow soft formation of CH 1-1 oilfield block,which solved the problems of the easy-to-appear new hole during tight hole situation in shallow soft formation,and poor downhole cleaning in high-inclination hold section.With on-site application in one well,wiper trip time was saved by 12.34%,and well prepared the wellbore condition for the successful application of full floating casing running in the first well at CH1-1 block.This technology is helpful for safe construction and efficiency enhancementin extended reach wells in shallow soft formation.
Chenghai1-1 oilfield blockshallow soft formationextended reach wellwiper trippilot bit
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