Design and application of a conformal coring tool for shallow soft sand layer

Abstract:

With the development of national resources exploration into the deep sea， it is necessary to obtain the deep sea stratum core.At present，mature coring tools have been developed for seabed sediments， soft and hard alternating strata， etc.However， there are still some technical barriers for shallow soft sand layer.On the basis of the existing TKP194-80 sealed pressure holding principle，the projecting conformal core bit is designed specifically，the ball valve structure is optimized，transparent liner and a check valve are added，the ball valve turn-over conformal coring tool is formed.The coring tool has the characteristics of small disturbance to sand layer， blockage prevention， etc，the test was successfully carried out in the shallow soft sand layer of ultra-deepwater oil and gas at 1500m in the South China Sea，the coring footage was 5.50m， the recovered sand core length was 5.00m， and the core recovery rate reached 90.91%.It breaks through the technical difficulties of coring ultra-deepwater shallow soft sand layer，it can provide key technical support for the exploration and development of ultra-deepwater oil and gas resources.