초록 ▼

Suction pressure pulses are generated within a borehole by closing a valve that interrupts the flow of a drilling fluid (e.g., drilling mud) circulating through one or more high velocity flow courses within the borehole. In one embodiment in which the suction pressure pulses are applied to improve t

Suction pressure pulses are generated within a borehole by closing a valve that interrupts the flow of a drilling fluid (e.g., drilling mud) circulating through one or more high velocity flow courses within the borehole. In one embodiment in which the suction pressure pulses are applied to improve the efficiency of a drilling bit, the valve interrupts the flow of drilling mud directed through the bit and thus through high velocity flow course(s) disposed downstream of the bit. Arresting flow of the drilling mud through the high velocity flow course(s) generates suction pressure pulses of substantial magnitude over a face of the drill bit. The suction pressure pulses provide a sufficient differential pressure that weakens the rock through which the drill bit is advancing and also increase the force with which the drill bit is being advanced toward the rock at the bottom of the borehole. However, the flow of drilling mud into an inlet port of the valve is not interrupted, so that fluid motors can still be used to rotate the drill bit. When the valve is closed, the drilling mud continues to flow into the valve and subsequently flows back into the borehole. The suction pressure pulses can also be applied to a short section of the borehole wall to produce seismic pulses, or to provide remediation of formation damage (by drawing fines from the wall of a borehole to enhance oil and gas production rates), or can be employed for descaling tubes within a borehole.

대표청구항 ▼

[ The invention in which an exclusive right is claimed is defined by the following:] [1.]1. Apparatus for generating a suction pressure pulse in a borehole in which a pressurized fluid is being circulated, comprising:(a) a valve having an inlet port, an outlet port, and a drain port, the inlet port

[ The invention in which an exclusive right is claimed is defined by the following:] [1.]1. Apparatus for generating a suction pressure pulse in a borehole in which a pressurized fluid is being circulated, comprising:(a) a valve having an inlet port, an outlet port, and a drain port, the inlet port of said valve being adapted to couple to a conduit through which the pressurized fluid is conveyed down into the borehole, said valve including a first member that is actuated by the pressurized fluid to cycle between an open state and at least a partially closed state, said first member, while in the at least partially closed state, at least partially interrupting a flow of the pressurized fluid through the outlet port so that at least a portion of said flow of the pressurized fluid is redirected within the valve without completely interrupting the flow of the pressurized fluid into the inlet port, the pressurized fluid that was redirected within the valve when the first member was last in the at least partially closed state subsequently flowing through the drain port and back up the borehole; and(b) a high velocity flow course coupled in fluid communication with the outlet port of the valve and having an inlet and an outlet, said suction pressure pulse being generated when the first member is in the at least partially closed state by substantially reducing the flow of the pressurized fluid through the high velocity flow course.