Patent Application
20170114595
The disclosure generally relates to standoffs, methods of conveying a tool into a wellbore, and assemblies for conveying.
Differential sticking occurs in wellbores while conveying tools into a wellbore. The differential sticking is caused by the tool digging into mud cake formed on the wall of the wellbore until a portion of the tool's surface area is exposed to the lower pressure of the surrounding geological formation. The pressure differential creates a force that clamps the tool to the borehole wall.
An example standoff includes a body. The body has a plurality of blades located thereon. Each of the blades has a contact side. The contact side of each of the blades has a radius that matches a shape of a wellbore wall that the standoff is going to be used with.
An example method of running a tool into a wellbore includes connecting a downhole tool with a cable. The method also includes connecting a standoff to the downhole tool. The standoff has a body with a plurality of blades located thereon. Each of the blades has a radius on a contact side that matches a shape of a wellbore wall that the downhole tool is conveyed into.
An example assembly for conveyance into a wellbore to perform an operation includes a downhole tool. The downhole tool has a standoff disposed thereabout. The standoff includes a body disposed about the downhole tool and a plurality of blades located on the body. Each of the blades has a radius on a contact side that matches a shape of a wellbore wall of a well that the assembly is going to be conveyed into.
Certain examples are shown in the above-identified figures and described in detail below. In describing these examples, like or identical reference numbers are used to identify common or similar elements. The figures are not necessarily to scale and certain features and certain views of the figures may be shown exaggerated in scale or in schematic for clarity and/or conciseness.
An example standoff includes a body. The body can be made from any material. Illustrative materials include steel, steel alloys, composites, elastomers, polymer (PTFE), or the like. A plurality of blades are located on the body. The blades can be located on the body by attaching or forming them onto the body. The blades can be attached to the body using mechanical fasteners to connect the blades to the body or using other now known or future known methods. Forming the blades on the body can include machining, casting, molding, 3D Printing; or other now known or future methods of forming blades. Each of the blades has a radius on a contact side that matches the shape of a wellbore wall. For example the radius of the contact side can be equal to the diameter of the wellbore.
The body can have a pair of halves. The halves can be joined by a hinge assembly at one end; thereby, allowing the body to be opened and shut. The halves can have a lock assembly located at another end thereof. The lock assembly can be a pin lock system, a latch system, or other now known or future known mechanical locking systems. In one or more embodiments, the body can have one or more lips formed on an inner surface thereof, and the lips can be used to align with grooves formed on a downhole tool. The lips can secure the body axially relative to the downhole tool and allow the standoff to rotate relative to the downhole tool. In another embodiment, the standoff can be locked in rotation with the downhole tool. For example, set screws, keys or stops in the groove, or other now known or future known methods of preventing relative rotation between the standoff and downhole tool can be used.
An example method of running a tool into a wellbore can include connecting a downhole tool with a cable. The downhole tool can be a tractor, logging tool, shifting tool, intervention tool, or the like.
The method can also include connecting a standoff to the downhole tool, wherein the standoff comprises a body with a plurality of blades located thereon, and wherein each of the blades has a radius on the contact side that matches the shape of a wellbore wall. Connecting the standoff to the downhole tool can include aligning a retaining lip on the inner surface of the body with a groove located on an exterior of the downhole tool.
In one or more embodiments, the standoff can be used as a stabilizer on a drillstring. For example, the standoff can be attached to the drillstring such that the drillstring rotates relative to the standoff. The standoff could be attached using a lip and groove design that allows rotation or other methods of affixation to the drillstring that allow relative rotation, such methods of affixation would be known to one skilled in the art with the aid of this disclosure.
The standoff 110 also has a plurality of blades located thereon. The blades can have contact areas that match the shape of the wellbore. For example, blade 122 has a contact area 123 and blade 120 has a contact area 121. The radius of the contact areas can be equal to the diameter of the wellbore. For example the contact areas 123 and 121 can have a radius of about 8.5″ if used with a wellbore having a diameter of 8.5″. By conforming the contact areas 123 and 121 to match the shape of the wellbore 100, the stability of the standoff may be increased, the potential for damaging or imbedding in the mud cake may be reduced, the risk of differentially sticking the standoff in the borehole may be reduced, and the drag force required for conveyance may be reduced. A detail of the blade 120 contacting the wellbore is depicted in
The standoff 220 has a body 222. The body 222 has a lock assembly 228 and blades 226 located thereon. The interior of the body 222 can have one or more retaining lips 224. The retaining lips 224 can align with the grooves 214. The standoff 220 can be substantially similar to those disclosed herein.
The contact areas 121 and 123 contact the wellbore 100.
Although example assemblies, methods, systems have been described herein, the scope of coverage of this patent is not limited thereto. On the contrary, this patent covers every method, apparatus, and article of manufacture fairly falling within the scope of the appended claims either literally or under the doctrine of equivalents.
