Conocophillips Company

Lars Hovda

James C Stevens

Dan Thomas Mueller

Amal C Phadke

Praveen Gonuguntla

Rick D Watts

Helen Haneferd

Stein Haavardstein

Brett Borland

Dianne Tompkins

Edvard Omdal

Hardy Hartmann Nielsen

Lars Vedvik

Tove Husby

Ole Jensen

Hardy Nielsen

Lars Vedvick

The invention relates to a cementing tool for use in oil and gas well decommissioning operations, in particular so called perforate, wash and cement procedures. The tool () is designed for running in a well on drill string and for jetting cement through previously formed perforations in the casing () to fill the outer annulus () with cement. The tool () has a cylindrical wall () which is formed from steel () and elastomeric () elements, whereby it is expandable between a first diameter in which it may be run down the well and a second, larger diameter deployed during cementing operations. (FIG.).

Behind casing cementing tool

Drilling a sidetrack in an open hole bore in a hydrocarbon reservoir of acid-soluble formation, e.g. carbonate formation, the creation of a sidetrack () in an open hole bore (for production of hydrocarbons from a carbonate rock formation (). Acid is delivered to the location () where a sidetrack is to be created; the acid dissolves away the formation and creates a trench () from which the sidetrack () may be drilled.

Method and apparatus for creation of an open hole sidetrack

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 (), in particular the washing or cementing operation using a rotating head () with nozzles () 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).

Behind casing wash and cement

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, in particular the washing or cementing operation using a rotating head with nozzles dispensing wash fluid or cement at pressure. A new design of bottom hole assembly is proposed in which the cementing tool has a relatively large diameter in order to optimize pressure whilst the wash tool has a relatively small diameter. The wash process, for a number of reasons, appears to be less sensitive to tool diameter and making the wash tool smaller reduces the overall risk of stuck pipe.

The invention relates to a cementing tool () and method for setting a cement plug. Instead of the conventional 'balanced plug', the technique involves pumping cement whilst pulling and rotating the tool. The cementing tool () includes nozzles () for jetting cement which are located in a relatively narrow region () of the tool and a larger diameter choke region () proximal of the nozzles (). The end of the tool () is closed off and tapered. The tool is passed down the well to a location where it is desired to set a plug, then cement is injected whilst rotating and withdrawing the tool. The jets of cement help displace existing fluid in the well thereby reducing mixing of the existing fluid with the cement, The choke region () increases the flow energy, whilst the tapered end () helps prevent disruption to the cement as the tool is withdrawn. The choke region () may be expandable to allow the tool to pass through a cased part of the well and then set a plug in an under-reamed open hole part of the well.

Setting a cement plug

The invention relates to a cementing tool for use in oil and gas well decommissioning operations, in particular so called perforate, wash and cement procedures. The tool () is designed for running in a well on drill string and for jetting cement through previously formed perforations in the casing () to fill the outer annulus () with cement. The tool () has a cylindrical wall () which is formed from steel () and elastomeric () elements, whereby it is expandable between a first diameter in which it may be run down the well and a second, larger diameter deployed during cementing operations.

The invention relates to the decommissioning of hydrocarbon wells. It concerns the artificial promoting or inducing of creep in the overburden formationsurrounding an oil well, so that the formation rockencroaches against the casingto form a seal. This avoids the need to plug the annulus between the casingand formationwith cement. The overburden may be caused to creep by reducing the pressure in the annulus, by applying heat to the overburden rock or by stressing the rock repeatedly to cause fatigue in the rock

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Tananger, Norway

Lars Hovda