A downhole tool for cleaning and sealing a wellbore includes a wash tool configured at a downhole end of the downhole tool to generate pulses of a first fluid at a first frequency and a first pressure for washing a target interval of a wellbore. The downhole tool further includes a plugging tool configured uphole or downhole from the wash tool to generate pulses of a second fluid at a second frequency and a second pressure for depositing a sealing plug at the target interval of the wellbore. The second fluid has a higher viscosity than the first fluid, the second frequency is lower than the first frequency, and the second pressure is higher than the first pressure.

A downhole tool for cleaning and sealing a wellbore includes a wash tool configured at a downhole end of the downhole tool to generate pulses of a first fluid at a first frequency and a first pressure for washing a target interval of a wellbore. The downhole tool further includes a plugging tool configured uphole or downhole from the wash tool to generate pulses of a second fluid at a second frequency and a second pressure for depositing a sealing plug at the target interval of the wellbore. The second fluid has a higher viscosity than the first fluid, the second frequency is lower than the first frequency, and the second pressure is higher than the first pressure.

A fluid diverter tool, system and method of diverting a fluid flow in a in a well, having: a tubular mandrel and a packer element affixed onto an exterior thereof and operable to sealingly engage an inside of a pipe body to divert a flow of a treatment fluid outwards through holes formed in the pipe bod; and a pressure relief device operable to open and relieve pressure from one side to another side of the packer element when exposed to a given pressure differential acting across the pressure relief device from said one side of the packer element, the pressure relief device also adapted to close when exposed to a lower than said given pressure differential acting thereacross from said one side of the packer element.

A wash tool comprises a mandrel with a central annulus and one or more lateral bores and one or more ring-shaped rotary hubs positioned about the mandrel adjacent to the one or more lateral bores. The rotary hubs comprise lateral bores perpendicular to the lateral bores of the mandrel such that pressurized fluid introduced to the central annulus of the mandrel impacts the inner surface of the rotary hubs and forces them to rotate, delivering pressurized fluid to the inner surface of a wellbore or tubular. The wash tool is modular and can be attached to a top sub or bottom sub, and may be used with or without a wireline. When used with a wireline, the wireline is insulated from the wash fluid by means of a tie-back and multiple seals.

The invention relates to a method of conducting a perf wash cement (“P/W/C”) abandonment job in an offshore oil or gas well annulus (2), in particular the washing or cementing operation using a rotating head (6, 8) with nozzles (7, 9) dispensing wash fluid or cement at pressure. Certain values of parameters of a washing or cementing job have been found surprisingly to affect the quality of the job, or the degree to which they affect the quality of the job has been unexpected. These include including rotation rate of the tool, the direction of translational movement of the tool, and the volume flow rate and pressure per nozzle of cement or wash fluid (and hence nozzle size).

A sectional pumping apparatus for well casing includes a discharge pipe, a submersible pump, a pump housing, a swab tool, and a central axis. The discharge pipe, the submersible pump, the pump housing, and the swab tool are concentrically positioned along the central axis. The discharge pipe includes a first tubular body and a flange connector. The flange connector is radially connected around the first tubular body. The submersible pump is hermetically attached to a pump end of the first tubular body. The submersible pump and the pump end are positioned within the pump housing as the first tubular body is hermetically attached to a top end of the pump housing through the flange connector. The swab tool is hermetically attached to a bottom end of the pump housing and is in fluid communication with the discharge pipe through the submersible pump.

A variety of systems and methods are disclosed for cleaning a wellbore ahead of a well tool. The well tool is deployed on a tubular conveyance to a depth into a well. An interior surface of the well is wiped ahead of the well tool to dislodge debris from the interior surface of the well as the tubular conveyance advances downhole. The debris is filtered ahead of the well tool as the tubular conveyance advances downhole to keep the filtered debris away from the well tool. The well tool may then be used to perform a tool function when the tubular conveyance has reached the depth, without being affected by the filtered debris.

A variety of systems and methods are disclosed for cleaning a wellbore ahead of a well tool. The well tool is deployed on a tubular conveyance to a depth into a well. An interior surface of the well is wiped ahead of the well tool to dislodge debris from the interior surface of the well as the tubular conveyance advances downhole. The debris is filtered ahead of the well tool as the tubular conveyance advances downhole to keep the filtered debris away from the well tool. The well tool may then be used to perform a tool function when the tubular conveyance has reached the depth, without being affected by the filtered debris.

A method and reactive treatment fluid for treating a wellbore for filter cake removal, including providing the reactive treatment fluid having a viscoelastic surfactant (VES) into a wellbore in a subterranean formation and attacking the filter cake via the reactive treatment fluid.

A method and reactive treatment fluid for treating a wellbore for filter cake removal, including providing the reactive treatment fluid having a viscoelastic surfactant (VES) into a wellbore in a subterranean formation and attacking the filter cake via the reactive treatment fluid.