Thru-Tubing intervention is increasingly used to service highly deviated, extended reach and horizontal wells which have become the typical well design in today’s field development.
DIVERSIFIED will develop and utilize tools and systems to perform advanced and cost effective thru-tubing intervention operations. The following tools and intervention systems are typical for well intervention operations but by no means are they limited to: logging, perforating, setting and retrieving plugs, opening and closing sliding sleeve, fishing, removing scale and debris, re-entry drilling, matrix acidizing and acid washing.
- Standard bottom hole assemblies
- Fishing tools
- Extended reach tools
- PDM’s and rotational tools
- Impact and fishing tools
- Clean out tools
- Thru-tubing accessories
- Packers and plugs
DIVERSIFIED will continue to develop and patent tools for its Thru-Tubing services such as the following vibrations tools:
- Impact tools: Used for “fishing” (removing) of stuck pipe or objects with oscillations / resonance in the well.
- Scale removal tools: Oscillations / resonance are used to break down scale and liquidize settled out mud and debris.
- Extended Reach: Used for extending reach in wellbores. Rotating tubing anchors – internal tubing cutting services.
Extended Reach Tools
Extended Reach tools is mainly aimed to reduce friction between coiled tubing and well bore in order to extend reach, but can also be used with other types of pipes. More than 30.000 coil tubing operations are done each year. It is estimated that approximately 5% of these operations are long horizontal wells in need of extended reach.
Extended Reach tools such as “Downhole tractors” currently exists in the market and is offered by competitors. Compared to the Downhole tractors the Extended Reach tools based on oscillations has the following competitive advantages:
- simple design, no wires or pulses
- does not rely on grip on the well bore
- easy to use
- cost effective
Impact Hammer
Oscillations are very effective as an impact tool and are used to remove stuck objects in a well such as: Completion plugs, drilling equipment and wireline equipment. The Impact hammer can also be used to broach scale or other type debris from a well or a pipeline. The oscillation technology is first used to extend reach to get to a stuck object and then uses the impact created by the same tool to free the object.
Competing products are hydraulic jars and other types of impact tools. Oscillation impact hammers has the following competitive advantages:
- eliminates coiled tubing fatigue during a fishing operation
- produces higher impact force than jars and other impact tools with the same OD (outer diameter) size
- increases over-pull and set down weight, thus increasing impact force.
Oscillation to remove scale
More than 30.000 coil tubing operations are done each year, and we estimate that approximately 10.000 (30%) of the operations is scale removal and wellbore cleaning where a oscillation based impact tool would be very useful and effective. The cleaning concerns removal of scale, debris, paraffin, etc. from producing wells and pipelines. It can also be used to remove cutting-beds and filter-cakes from well bores and it can be run with other pipe types than coiled tubing.
Oscillation Impact tools has the following competitive advantages:
- Intensifies the jetting force down hole, thus decreasing the requirement for high-pressure equipment on the surface, thereby reducing cost and increasing safety.
- accepts acid as main fluid, thus optimizing cleaning possibilities
- combines high pressure with mechanical impact, a combination that significantly improves cleaning performance
Oscillation simulation software
The oscillation simulation software is designed for calculating weights, forces, stress, torque, friction, circulation pressures in tubulars and annulus, wellbore hydraulics and along-hole depth corrections for well intervention and drilling operations. The software can predict along-hole reach, lock-up depth, maximum reach in a given wellbore and therefore the feasibility of a well intervention or drilling operation.
The software is based on results of intensive experimental and theoretical studies on along-hole friction forces, buckling and post-buckling of coiled tubing and other generic tubular at Rogalandsforskning (Rogaland Research Centre). The software has been validated by test results and field data over a period of several years.
The parameters simulated are:
- Frictional forces along-hole in a given well.
- Dynamical simulation of the behavior of imposed oscillations to the tubular to
calculate the reduction in effective friction coefficient. - Impact produced onto a object if the oscillations technology is used to free stuck
objects - Finally, a tubular forces calculation with the reduced friction, i.e. with the oscillation
technology.
The results presented by the software are valid for any cylindrical tubular, including coiled tubing, drill pipe, casing, gravel pack screens etc. This fact is of great interest to the potential use of oscillation technology as it can have many applications.
Development of a reliable software model for the oscillation technology is viewed as and has proven to be essential for its commercial success. The reason for this is that professional engineers rely heavily on such simulation tools in the planning process of a drilling or well intervention operation.