Going where coiled tubing can't go
The Bore Rat is a versatile autonomous tool for performing a variety of downhole functions.
Using technology that has been around for years, a Houston firm plans to demonstrate that artificial intelligence offers a practical alternative to traditional downhole tools. Stepping back from the ambitious downhole factory concept Baker Hughes announced a year ago, IIC, which works with IS Robotics, plans a series of downhole tools that employ artifical intelligence to conduct a series of functions.
Neil de Guzman, President and CEO of IIC, said the current downturn in oil prices has halted a lot of research projects and delayed the adoption of new systems such as smart wells or the downhole factory. IIC currently is working on a number of independent projects that would allow the industry to enjoy the benefits of these technologies at a lower cost, and also positioning the applications between the "blue sky" ideas of the downhole factory and the way things are done now.
The biggest obstacle artificial intelligence (AI) and robotics technologies face are perceptions in the industry. The idea of turning loose an autonomous tool downhole is frightening to many people in drilling and production and de Guzman said he was running up against the "not in my well" mindset as he shopped around the capabilities of the technology.
Some of the changes made in the approach were semantic. For example, Guzman doesn't call these "tools" robots. The terms are "bore rat" or "well rover." Other adjustments went to the heart of industry resistance. IIC stripped out all the bells and whistles of its technology to design a simple tool, based on existing technology that could perform simple fishing operations.
The theory, according to de Guzman, was that a well with stuck pipe, or in need of a fishing job already had a problem. The chances were good that someone in this situation might be more inclined to try a new technology, thinking there was little to lose.
Tool designThe tool IIC designed is simple, given the potential for more advanced enhancement. This was intentional. The idea was to put something on the market that would prove the technology is reliable and sound.
This device has the ability to go downhole, recognize where the problem is, cut or retrieve the stuck pipe and return to the surface on its own. De Guzman said there were three original designs considered for this tool. The most difficult parameter was designing a tool that could travel through the highly variable diameter of a well.
The first design could traverse the wellbore using an inching brace system, but it was painfully slow. The second design was faster, basically spinning downhole like a corkscrew, but couldn't deal with the decrease in ID.
The design that finally won out was a "caterpillar" tractor that was able to roll downhole at an acceptable speed and deal with the large changes in ID. The tool has locomotion in the rear and sensors in the front. This is an essential feature for a tool that will be exploring damaged tubulars and seeking out broken pipe.
The tool can be programmed to recognize a variety of features that would identify the specific fishing target and rotting pipe hazards, track descent, and also carry tools and retrieve fished objects. The goal of this onboard intelligence is two-fold:
- To identify and retrieve the fishing target
- Avoid getting stuck, running down the batteries trying to get past an impossible obstruction, or fall out the bottom of a rotten pipe string.
Coiled tubing alternativeDe Guzman said that fishing jobs are just one of the tool's abilities. The tool is designed with the mobility to the rear, logic units in the middle, and a variety of battery packs and connections for a variety of logging and other tools at the front. As an autonomous logging tool, the bore rat has a variety of advantages over conventional wireline systems. Chief among these is that the tool can travel under its own power with no connection to the surface. This is particularly advantageous in highly deviated wells, those with a departure form vertical of more than 55°.
Such an angled borehole is difficult to access with conventional logging tools run on coiled tubing, which translates to higher costs. The bore rat can accomplish the same thing, saving a third of the cost and eliminating the need for a rig or coiled tubing.
The bore rat tool is compact enough that it could be flown out to the well on a helicopter in a couple of rifle cases. De Guzman said this tool could conceivably change all the cost elements associated with logging wells. Because of the cost savings and portability of the equipment, the bore rat could be used for a variety of downhole data acquisition.
Moving logging toolsThis technology relies on conventional logging tools and is designed to work with a variety of proprietary systems. All the IIC tool does is transport the logging tools downhole and bring them back. The simplicity of the operation makes it practical to do several logs over an area of interest and detailed logs of wells that are only marginally profitable. Such detailed logging would allow engineers to design a more effective stimulation package and increase production during workover activities.
The goal of IIC is to combine two existing technologies to develop a new application that increases the value of both. A version of the bore rat tool is now under contract to Baker Hughes. This fishing tool application is tighthole, but should prove the value of the technology to the industry, de Guzman said. From that viewpoint, this one tool could be used in a variety of applications, from PWD to fishing to providing support for a new generation of smart wells.
It is possible that this tool might some day be added to the equipment already on a rig so that logging and fishing operations would be quicker, simpler, and less expensive. De Guzman said it is ironic that the biggest current limitation to the development of this technology, namely the low oil price environment may ultimately provide the market for such inexpensive alternatives.
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