QGC has solved a technical problem in Queensland coal seam gas extraction that not only saved hundreds of thousands of dollars but improved safety and resulted in a global innovation and technology award.
Australia often takes on the world and wins. It is something about the ‘can do’ attitude that rolls over obstacles that other nations falter at. It is also often the simple looking innovations that attract the most attention and often have the greatest impact.
Gerard Norton is an engineer at QGC (Queensland Gas Company). Gerard was tasked with a problem to solve around the monitoring of Coal Seam Gas. There was a need to more accurately estimate the yield from the respective coal seams through pressure monitoring whilst adjacent gas wells were in production. Previous attempts and methods had been proven unreliable due to the difficult process of installing and sealing the gauges in the monitoring holes at the depth required.
It is necessary to estimate and model how productive a coal seam will be in order to value a CSG company’s assets and the total amounts of coal seam gas in reserve. Traditionally a core sample is taken and studies are carried out on the coal to work out how productive the coal seam is likely to be. This means lots of testing and lots of holes being drilled and plugged with cement to meet regulatory requirements for abandonment of wells that are no longer required.
This initial coring process gives information on the possible productivity of the wells to be drilled in the surrounding area but does not give an indication of the depletion likely to occur as the surrounding wells go into production. Coal seam gas fields typically exhibit extreme heterogeneity to assist in the development and calibration of reservoir models, specific monitoring wells are often used to acquire reservoir pressures and temperatures as part of an integrated reservoir surveillance program.
Queensland Gas Company – Innovation rewarded
The solution was to take one of theses core holes, re-enter it and place vibrating wire piezometers attached to capillary string coil tubing. Gauges were positioned alongside selected reservoir intervals. These holes measure between 350~900 metres deep. Up to 8 gauges are required to be set at varying depths.
The gauges need to be isolated from each other in order to be able to compare the readings at different depths. The main problem that presented itself was that the cables were ‘bunching’ and providing the opportunity to introduce micro annulars which could lead to communication between each gauge and therefore, introduce pressure and temperature errors between these respective zones.
A cable spacer was needed to allow the cement grout to make a perfect seal around the hole, thereby isolating each zone needing to be monitored. Through QGC, Gerard searched for a company that was willing to take on the challenge of designing and manufacturing a product that could solve this problem. It wasn’t as simple as sending a brief and getting a product back. After much discussion B&C Plastics were appointed and they designed and created the cable spacer using their 5 step manufacturing process.
The result was a product that enabled the installation of the gauges and cabling using a 2 part piece that clipped together rather than the 11 parts that had previously been used. This reduced the install time from approx 15 mins to around 2 mins and reduced a day and a half process to around 4 or 5 hours.
According to Gerard “It used to be a very time consuming process. We now estimate to be saving more than $300,000 per annum. This is a combination of reduced installation time and a reduction in the actual product cost. Creating parts with plastic injection moulding is a very cost effect process.”
“B&C Plastics were the right partners for this project, the owners of B&C Plastics (Royston and Bob) are good blokes, extremely professional and have a ‘can do’ attitude. As the mould designer Bob produced the components with the latest computer aided design. This allowed the concepts to be shown at meetings as 3D models which ultimately led to the funding for the project to be approved. I was involved at every step of the manufacturing process directly with the owners of B&C.”
Features of the cable spacer
- Less Cost versus the conventional solution.
- Addressed health and safety concerns by speeding up the process so employees are spending less time at the mouth of the drill hole.
- Environmental benefits as one hole can monitor every production hole within 1500 metres.
- All that is visible on the surface once the hole is filled is a 1 metre square area of concrete with a transmitter.
This project is a great example of what happens when an idea is presented to the right manufacturing expertise. QGC are extremely proud of what has been achieved and what started as a solution for QGC in Australia is now being rolled out globally through British Gas. The exciting thing for B&C Plastics is that there are many other coal seams that can benefit from this product and there are even wider applications such as stress monitoring in concrete bridges or buildings.
QGC are now working with B&C Plastics on the second and third generation of the product which will combine two existing products into one, not only spacing the cables but centralising the gauges in the hole.
Queensland Gas Company – Innovation rewarded