A well production line
As energy demand continues to rise, energy companies are finding new ways to help meet it. One way is to open up new resources of gas trapped tightly in dense rock. The gas flows less easily and is harder to extract, which can drive up costs. A new drilling approach being developed for reservoirs that require many wells could make the process quicker, cheaper – and with less environmental impact.
Conventionally, engineers drill a well from start to finish using a huge multi-purpose rig. But applying this approach to produce tight gas – where many wells are needed – is slow and costly. Shell has formed a joint venture with China National Petroleum Corporation to develop a more effective way: using a series of smaller, mobile rigs for each stage of the drilling process and automating many tasks.
In this approach the first rig, for example, would drill the top part of the hole, a second would drill down further, and the third complete the well. Each rig will be designed for a specific task and its compact size will reduce environmental impact.
The rigs and other equipment will be tailored to the conditions in a particular field and then mass produced. They will also include the latest drilling technology, such as a software programme to drill more smoothly.
The rigs can be mounted on trucks to move to the next well. At any one time a number of wells will be in different stages of completion. Drilling in parallel in a more automated way speeds up the process and brings down costs.
An electronic information system will be connected to the rigs and record details of well conditions and how the rigs are performing. The system will use this information to make automatic adjustments, for example to the speed and direction of the drill.
Trained rig crew are in short supply. The automated control system will reduce the need for rig workers, lowering safety risks and human errors.
Shell and CNPC are automating other aspects of the process, such as moving drill pipes.
The equipment for this approach – called a well manufacturing system – is currently being constructed. Arrow Energy will use the approach for the first timein Queensland, Australia in 2013, improving efficiency and limiting environmental impact.