DRILLING & PRODUCTION

William Furlow
Houston

The ProEngineer prototype solid modeling CAD system is used by ABB Vetco Gray in the design of such complex projects as this HT horizontal tree configured for the Marathon Arnold project. [25,915 bytes]

New dual BOP aimed at deepwater

Hydril has announced the design of a new blowout preventer configuration designed to boost flexibility in deepwater. The Dual GX 18 3/4-10,000 Annu-Flex combines two annular 18 3/4 in. BOPs with a flex joint. It can be used as the upper BOP package in water depths of more than 10,000 ft. The integrated flexjoint provides up to plus or minus 10° of flexure and is rated at 2,000 psi working pressure, with a maximum tension of 2 million lb. The entire system is 179 in. tall and weighs in at 54 tons. The unit can provide annulus closure on pipe or on open hole. An optional integrated flex joint rated to 5,000 psi working pressure is also available.

Indigo uses drill data for foundation design

An Australian geotechnical consultancy has developed a method for using routine exploration data in platform foundation concept designs. The data used, mainly preliminary geotechnical engineering data is process and interpreted by engineers looking for information on the soil stratigraphy and the indicative strengths in the first 100-150 meters beneath the sea floor. Using this information, the geotechnical engineers can identify viable foundation options.

The approach is called Interpretation of Drilling Information with Geotechnical Objectives (INDIGO). In addition to being cost effective, the information gathering technique does not disturb normal exploration well drilling time.

The INDIGO approach has been successfully used offshore Western Australia in the Timor Sea, according to Brian Ims, a Senior Geotechnical Engineer with Douglas Partners, the system developers. Ims said the technique integrates geophysical data and drilling behavior during the spudding of the well. A major component of the work uses the same data found in a conventional mud logger's instrumentation package, including torque, rpm, weight on hook, penetration, and time. This information, combined with survey geophysics offers a detailed picture of the stratigraphy in the first 150 meters below the mud line.

Other useful information that can be gathered offshore includes the collection of seafloor samples of the seabed returns using an ROV, and the collection of samples of material adhering to the drill bit on its return. These data provide a range of information including micro-palaentological dating and establishment of the geological and dispositional characteristics of the strata, and the soil types at discrete depths.

Fluid may overcome acid limitations

Tested in the prolific Austin Chalk reservoir of West Texas, the Arcasolve non-reactive fluid has proven to be an alternative to acid stimulation treatments. Acids are effective for increasing fracture conductivity, but have several drawbacks. Hydrochloric acid, for example, is highly reactive and spends close to the injection point creating wormholes and cavities that increase formation damage.

Because Arcasolve is non-reactive, it can be pumped from surface to fill horizontal sections and the surrounding fracture network. Acid is then produced in-situ within the wellbore and fracture network during shut-in. While shut-in, Arcasolve begins to dissolve the carbonate in the fracture. As the carbonate dissolves the level of soluble calcium or magnesium in the acidizing fluid rises.

The increased level of dissolved calcium and or magnesium in produced water, after the Arcasolve treatment allows the operator to measure the amount of in-situ dissolution of carbonate within the fracture network. By comparing these levels to those in the produced water before the treatment a cumulative quantity of dissolved calcium or magnesium can be reached.

Arcasolve treatments can be pumped using standard oilfield equipment. The chemicals are low hazard and formulated Arcasolve acidizing fluid and back produced fluid are non-corrosive and biodegradable.

ABB battling size with transparency

With turnaround times for new technology and even routine fabrication work going at a premium, ABB Vetco Grey has brought on-line two new systems designed to make the most of work the company has already done.

In the past, the company's three engineering groups in Houston, Aberdeen, and Singapore were not only separated by physical distance but by non-compatible computer systems and piecemeal records keeping that had some designs on the network, others on individual hard drives, and some in hard copy form.

Using a computerized product information management system (PIMS), the company has aligned all part numbers, documents, and drawings world wide. This means a Houston engineer can pull up a product designed in Houston on a workstation in Singapore using the same part number he used in Houston. In addition to standardizing the part numbers and other data, the system culls redundancies and offers engineers the full range of ABB Vetco Gray designs to build on in new projects. This saves warehouse space, where identical parts with different part numbers were stored side-by-side. It also saved engineers time because much of the work they had to do from scratch before could now fall back on previous designs already in the system that require only modifications.

ABB Vetco Gray, according to Louise Rennie PIMS Project Engineer, is a collection of companies brought together, and as such draws a lot of its value from this design legacy. PIMS allows ABB Vetco Gray engineers to make the most of this legacy while improving on past designs. A companion to this software is the Pro/EngineerRegistered solid modeling CAD system.

Much as the PIMS, this system organizes the company's many designs, but does so in a way that allows the designs to be modified for new products. Where PIMS offers documentation Pro/E offers full 3D information on the designs.

Think of PIMS as the card catalogue and Pro/E as the library. These computer aided designs can be constructed, manipulated, enhanced, tested, detailed and assembled at a computer workstation. Tim Cooper, Senior Technical Specialist and Pro/Engineer Systems Administrator said the computer solid modeling approach allows designs to be optimized and points out inconsistencies and part interference so that a prototype is actually built in the computer rather than in the shop. The computer can even test the designs once they are complete. Cooper said the ability to take a design to the prototype stage without leaving the desktop not only saves money, but significantly shortens the manufacturing cycle time. The program even produces a parts list that can be modified to include prices.

In one software package, Pro/E offers design, manufacturing and QA solutions which can create a seamless process from design to shop floor to quality testing all using computers.