Study On Well Clean-out By Pack Partition And Water Hammer

The technology of well clean-out by pack partition and water hammer is developed in hydro-geology survey of key area along Hei-He river. This technology not only can clean out mud and land-waste on well-face thoroughly but also can be work on old well which mud solidify on well-face over a long period of time. Besides, this technology combine the well-clean and pumping test so that realize integration,reduce intensity of work and improve consistency.This paper introducing percolation theory and water hammer theory to expound the theory of well clean-out by pack partition and water hammer. To clean-out well,pack-partition enhance the osmotic pressure by double-packer and water-hammer caused by turn on or off pump which can trigger huge instantaneous pressure. This paper simplify the formation and assuming something so that deduce the formula of well clean-out by pack partition and water hammer. Restricted by real formation, the formula of well clean-out by pack partition is only a empirical formula which could not calculate the real pressure of water-hammer.Study on the theory of percolation and water hammer, we can find several factors influence well clean-out. Such as borehole diameter, modulus, pump duty, length of pack partition, position of pump, interval time, formation anthropic factor, equipment factor and so on.There factors are grouped according can be regulated in time or not. Well clean-out by pack partition and water hammer work well in solid formation, and do not apply to uncemented formation. The factors can be regulated in time including pump duty, length of pack partition, position of pump, interval time. The rate of wellflushing in proportion to pump duty and inversely proportion to length of pack partition. Pump should put on the end of pack partition.