In USA during the oil crisis finding alternative sources of energy was made a priority. In the 1970’s and 1980’s tax concessions made exploration for gas from unconventional sources such as shale, sand and coal gas fields attractive These ‘unconventional sources’ became an attractive proposition for many exploration companies. By the 1990’s although these concessions had expired the general increase in exploration and extraction cost for the whole energy market had made these unconventional sources worth more than a second look.

One region of astonishing growth in land based gas extraction is the Powder River Basin which is located in north-east Wyoming. The basin has proved itself to have easily located reserves that are estimated to be between 10 trillion and 30 trillion cubic feet of gas. What really sets this field apart is the speed and bargain basement price of exploration and extraction compared to many other fields with similar potential.

Coal Bed Methane (CBM) wells in the Powder River Basin are generally between 400 and 1,300 feet deep and take no more than two to three days for drilling and completion. The well depth and the time taken for completion mean that each well typically costs between $30,000 and $50,000 each. It may sound like a high figure per well but if you take into account that CBM wells in the San Juan Basin costs upwards of $300,000 it is a steal! Drilling and completion costs for this region are currently below $0.20 per Mcf (thousand cubic feet) easily one of the lowest development costs for the extraction of gas reserves.

Thunder Creek Gas Services LLC was formed to service the Wyoming's Powder River Basin with 126-mile 450-MMCF/D capacity gas gathering system and related facilities. The 24in line will have access to KN Interstate’s (KNI) existing Pony Express line, KNI’s proposed Pathfinder line, the Colorado Interstate Gas system, and Wyoming Interstate Co.’s planned Medicine Bow lateral. The $100 million project was designed to bring the gas from the Wyoming's Powder River Basin to an interstate market. Part of the project was the post extraction processing facilities designed in two phases by Pearl Development, Bailey, Colorado, USA.

Pearl Development Company is an independent engineering, business development and construction management company. Pearl was founded in 1993 and during that time has completed over 100 projects in North and South America, Europe, Asia and Australasia. Pearl’s projects completed to date represent a combined through-put of 2 BCFD of natural gas, over 4,500 GPM of gas treating solvent circulation and over 45,000 BPD of NGL fractionation. Pearl has a worldwide reputation for delivering state of art engineering solutions for NGL recovery, fractionation, compression, dehydration and gas treating systems. This made them an obvious choice for the design of the treatment plant for the Powder River Basin gas recovery system. The award for the engineering design was broken down into two separate projects.

Pearl’s first project for Thunder Creek Gas Services LLC consisted of over 50 pieces of equipment and process pipes sizes up to 24” (600mm) in diameter. The aim of the process was to ‘sweeten’ the extracted gas by the removal of naturally occurring impurities. The second of the Powder River Basin projects was for the design of a Natural Gas Liquid (NGL) extraction process. As with all naturally extracted gases there is a portion of hydrocarbons – NGL’s that are best removed from its methane base prior to distribution. The process consisted of over 36 pieces of equipment with piping up to 16” (400mm) in diameter.

Prior to starting these projects Pearl decided that if they were to meet the aggressive project schedule with a small design staff they would have to use design tools that would provide efficiencies and integration between the engineering, design, procurement, and construction functions. Additionally due to the international nature of their work these tools would need to be flexible enough to work in Imperial or Metric units. Pearl decided that if they were to look at 3D piping design they would have to look to the AutoCAD market place.

There were few packages on the market that could offer them the ease of use plus the powerful 3D tools that they felt were needed. It was obvious they were going to need both If they were to deliver the quality product that their clients demanded. After extensive evaluations Pearl decided on CADWorx/PIPE from COADE, Houston, Texas in the USA.

Pearl’s selection of CADWorx/PIPE gave them what they needed. From the ability to produce 3D models, 2D drawings, fabrication isometrics, and bills of material and provided bi-directional links to COADE’s CAESAR II stress analysis package. Pearl found CADWorx/PIPE easy to learn, implement and use. In fact Pearl Development’s designers were up and running in just two days after using the manual’s self paced and online tutorials.

Designers all think in 3D, but using a CAD tool to actualize those concepts and thoughts is not always as easy as it may seem. Every component, whether it be a fitting, valve, piece of equipment or specialized item has to be defined in all three dimensions. This enormous task was made much easier for Pearl because nearly all of the fittings that Pearl use for their designs were included with CADWorx/PIPE right out of the box. The program is shipped with piping components grouped by material including carbon and stainless steel, FRP and PVC. Various fitting end types such as butt weld, flanged, clamped, socket welded and treaded are also supplied in Metric or Imperial units.

Pearl utilized CADWorx/PIPE's Specification Builder/Editor to develop piping components not included with the package. Pearl found that using CADWorx/PIPE's specification driven routines meant that each fitting was placed exactly to project specifications.

Additionally the workgroup features of CADWorx/PIPE also made it easy for multiple designers to work on different parts of the model. This could be done while viewing other parts of the model that were being worked on. These areas could belong to other designers or even other disciplines. Thus taking the guesswork out of routing piping systems therefore increasing accuracy and output, and reducing design hours.

Another advantage was that the automatic spool drawings and fabrication isometrics that were created could be modified and those changes exported to the 3D model or visa versa. This feature has the benefit of enabling engineering firms to perform ‘one-stop’ modifications and updates.

With CADWorx/PIPE many of the traditional steps design offices take were no longer required, but that is not to say that the quality of the end product is compromised. On the contrary creating a efficient and safe design and deliverables are produced with the minimum of effort. For Pearl Development this meant that designers spend their time on their prime

After 18 months Pearl can honestly say that the decision to move to CADWorx/PIPE as a 3D piping design tool has greatly benefited the company. Pearl also feel that its clients have likewise benefited from the delivery of a quality product. As with all newly introduced tools and procedures it is felt that more can be extracted from these models. One undocumented and immeasurable feature of this implementation is the enthusiasm of the those working with the product. As stated before designers think in 3D, but there can be no substitute for seeing one’s designs in that form.

Pearl continues to use CADWorx/PIPE as an core part of their engineering design suite.

A full version of this article will appear in the November issue of Hydrocarbon Engineering magazine.