초록 ▼

A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to

A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC-CO2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC-CO2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC-CO2 within the pores of petroleum formations is significantly higher than that of water, making jet erosion using SC-CO2 much more effective than water jet erosion. SC-CO2 jets can be used to assist mechanical drilling, for erosion drilling, or for scale removal. A choke manifold at the well head or mud cap drilling equipment can be used to control the pressure within the borehole, to ensure that the temperature and pressure conditions necessary for CO2 to exist as either a supercritical fluid or a dense gas occur at the drill site. Spent CO2 can be vented to the atmosphere, collected for reuse, or directed into the formation to aid in the recovery of petroleum.

대표청구항 ▼

1. A method for using at least one of a supercritical fluid and a dense gas to increase an efficiency of a drilling operation, comprising the steps of:(a) providing a material that exists in one of a supercritical phase state and a dense gas phase state at a temperature and a pressure associated wit

1. A method for using at least one of a supercritical fluid and a dense gas to increase an efficiency of a drilling operation, comprising the steps of:(a) providing a material that exists in one of a supercritical phase state and a dense gas phase state at a temperature and a pressure associated with a drill site where the drilling operation is performed; (b) supplying the material to the drill site; (c) exposing the material that is being supplied to a temperature and a pressure that causes at least a portion of the material being supplied to change its phase state to one of a supercritical fluid and a dense gas; (d) ejecting a fluid stream of said material being supplied onto said drill site; and (e) performing said drilling operation, said material that is ejected increasing an efficiency of said drilling operation.