Browse Prior Art Database

Device and process allowing reverse fluid circulation methods in conjunction with any downhole tool requiring standard circulation fluid flow

IP.com Disclosure Number: IPCOM000250599D
Publication Date: 2017-Aug-07
Document File: 4 page(s) / 462K

Publishing Venue

The IP.com Prior Art Database

Abstract

The proposed invention is for a series of fluted subs which when used with dual-wall or fluted drill pipe, standard to reverse circulation operations, allows traditional mud motors, MWD/LWD mud pulse tools, drill bits, or other downhole tools requiring standard fluid flow to be designed and function as normal. This would allow a step change in the way any borehole is cleaned, greatly enlarge the allowable borehole diameter operating envelope, as well potentially reducing the amount of water, or other base fluid, required for drilling operations.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 43% of the total text.

Title: Device and process allowing reverse fluid circulation methods in conjunction with any downhole tool requiring standard circulation fluid flow

Abstract: The proposed invention is for a series of fluted subs which when used with dual-wall or fluted drill pipe, standard to reverse circulation operations, allows traditional mud motors, MWD/LWD mud pulse tools, drill bits, or other downhole tools requiring standard fluid flow to be designed and function as normal. This would allow a step change in the way any borehole is cleaned, greatly enlarge the allowable borehole diameter operating envelope, as well potentially reducing the amount of water, or other base fluid, required for drilling operations.

Description: This invention is for a series of subs (items 3,4, and 5 in the drawings below) which provide means for diverting the fluid flow path during reverse circulation with dual wall, or fluted, pipe in a preferable manner to power conventional MWD/LWD tools, drilling motors, or any other fluid driven downhole equipment, while still maintaining the favorable hole cleaning qualities of reverse circulation. This invention results in only subs being manufactured as 'dumb iron' rather than re-designs of more complicated systems such as MWD/LWD tools, drilling motors, rotary steerable steering heads, turbines, etc. The premise behind the invention is capitalizing on fluid hydraulics and preferential flow paths due to differential pressures. The combination of these components results in the required fluid diversion necessary to power conventional drilling assemblies while maintaining the hole cleaning capabilities of reverse circulation.

The invention uses three newly invented subs in combination with existing dual wall, or fluted, drill pipe and downhole drilling assemblies. The subs can be manufactured at any machine shop capable of boring multiple holes through high yield strength steel. Each sub will require a larger center bore to be milled out from a single piece of cylindrical steel. In addition to the large bore, additional small flutes will also need to be milled along the circumference of the remaining wall-thickness of the steel pipe. Due to the reduction in overall steel material remaining after the bore and flutes are milled, high yield strength material is likely required to deliver the necessary axial and torsional load capacity requirements for drilling large diameter holes.

An annular pack-off needs to be included at surface to prevent fluid from escaping the wellbore annulus and to ensure that the hole remains full, providing a hydrostatic pressure barrier as well as a secondary seal barrier on the annulus for well control purposes. A specialized inner-pipe preventer will be required for a secondary barrier on the inner pipe flow paths. A combination of a custom kelly-like device, washpipe and pack-off, and short fluted pipe joints could be utilized for this purpose. The use of the seal, in combination with pressure transducer...