Pressure Pulse Reach Extension Technique

Abstract

A pressure pulse tool and techniques that allow for a reciprocating piston at a frequency independent of a flow rate of fluid which powers the reciprocating. The architecture of the tool and techniques employed may take advantage of a Coand{hacek over (a)} or other implement to alternatingly divert fluid flow between pathways in communication with the piston in order to attain the reciprocation. Frequency of reciprocation may be between about 1 Hz and about 200 Hz or other suitably tunable ranges. Once more, the frequency may be enhanced through periodic exposure to annular pressure. Extended reach through use of such a pressure pulse tools and techniques may exceed about 2,000 feet.

We claim: 
     
         1 . A method of advancing a downhole conveyance device through a deviated section of a well, the method comprising:
 deploying the downhole conveyance device into the well with a fluid flowing therethrough at a given rate;   alternatingly diverting the fluid flow between pathways of a pressure pulse tool for reciprocating a piston thereof at a given frequency independent of the given rate; and   advancing the conveyance device through the deviated section during the reciprocating of the piston and to a target location in the well.   
     
     
         2 . The method of  claim 1  wherein the reciprocating of the piston periodically interrupts fluid flow to generate pressure pulses as an aid to attaining the extended reach. 
     
     
         3 . The method of  claim 1  wherein the alternatingly diverting of the fluid flow between pathways further comprises alternatingly deflecting a diverting mechanism of the tool between the pathways to guide the fluid flow via a Coand{hacek over (a)} effect. 
     
     
         4 . The method of  claim 1  further comprising periodically exposing the reciprocating piston to annular pressure in the well. 
     
     
         5 . The method of  claim 1  further comprising tuning the given frequency to between about 1 Hz and about 200 Hz. 
     
     
         6 . The method of  claim 1  further comprising performing an application in the well at the target location with an application tool coupled to the downhole conveyance device. 
     
     
         7 . A pressure pulse tool for a downhole device, the device configured for use in a well and to carry a fluid at a given flow rate, the tool comprising:
 a housing coupled to the downhole device for directing the fluid therethrough; and   a piston located within the housing for shifting at a given frequency independent of the flow rate.   
     
     
         8 . The pressure pulse tool of  claim 7  wherein the given frequency is between about 1 Hz and about 200 Hz. 
     
     
         9 . The pressure pulse tool of  claim 7  wherein the housing defines a primary channel in fluid communication with an uphole bore of the downhole device for the directing of the fluid, the tool further comprising:
 a nozzle-shaped region of the housing in communication with the primary channel, the nozzle-shaped region having a neck leading to first and second fluid pathways in fluid communication with the piston; 
 a diverting mechanism at least partially located within the neck for guiding fluid from the primary channel and alternatingly between the first and second pathways for the shifting thereof at the given frequency; and 
 a controller for controlling a rate of the alternating of the diverting mechanism between the pathways. 
 
     
     
         10 . The pressure pulse tool of  claim 9  wherein the piston is in periodic fluid communication with an annular port to the well. 
     
     
         11 . The pressure pulse tool of  claim 9  wherein the diverting mechanism is a Coand{hacek over (a)} implement. 
     
     
         12 . The pressure pulse tool of  claim 11  wherein the Coand{hacek over (a)} implement is one of a piezo-based implement and a magnetically actuated implement. 
     
     
         13 . The pressure pulse tool of  claim 12  wherein the piezo-based implement comprises piezoceramic material layers. 
     
     
         14 . The pressure pulse tool of  claim 12  wherein the magnetically actuated implement comprises north and south polarized end portions, the tool further comprising a magnetic coil located at least partially in the neck and adjacent the end portions. 
     
     
         15 . An oilfield assembly for use at an oilfield, the assembly comprising:
 a conveyance device;   a bottom hole assembly coupled to the conveyance device and having an application tool for use at a target location in a well; and   a pressure pulse tool of the bottom hole assembly, the tool having a housing in fluid communication with the conveyance device for directing fluid therethrough at a given flow rate for reciprocating a piston at a frequency independent of the given flow rate.   
     
     
         16 . The oilfield assembly of  claim 15  wherein the conveyance device is one of tubing string, coiled tubing, drill pipe, casing, production tubing and a liner. 
     
     
         17 . The oilfield assembly of  claim 15  wherein the pressure pulse tool comprises a Coand{hacek over (a)} element for directing fluid interchangeably between pathways at a given rate to effect the frequency of the reciprocating of the piston, the bottom hole assembly further comprising:
 a downhole power source for the Coand{hacek over (a)} element; and 
 a controller for regulating the rate of fluid interchange between the pathways. 
 
     
     
         18 . The oilfield assembly of  claim 17  further comprising a telemetric line coupled to the controller and to surface equipment at a surface of the oilfield to allow operator direction of the controller. 
     
     
         19 . The oilfield assembly of  claim 18  wherein the telemetric line is a fiber optic line.