October 2003 ///

Special Focus

Advances in fatigue design: Curvature index theory

Fatigue is the leading cause of drill string failures during rotary drilling. Complexity of the fatigue mechanism and inability to account for cumulative fatigue damage make absolute fatigue life prediction impractical. However, drill string and trajectory designs can be optimized to significantly reduce fatigue damage. This is accomplished by using fatigue life prediction models to analyze relative effects that different design options will have on fatigue life, and to quantify the advantage of one design over another.

Aphron-based drilling fluid: Novel technology for drilling depleted formations

This article describes development and application of the specialized micro-bubbles – based drilling fluid by M-I L.L.C., for controlling downhole mud loss in a depleted reservoir for NAM (Nederlandse Aardolie Maatschappij BV) in the North Sea. Key issues of this project were excessive overbalance drilling conditions (>5,000 psi) leading to the risk of highly expensive lost circulation, and open perforations in the upper producing zone, requiring temporary sealing during drilling. The well was successfully drilled to TD without any drilling losses. Lab methods used to generate appropriate formulations, operational procedures and field application are discussed.

Real real-time drill pipe telemetry: A step-change in drilling

For over 50 years, technology has been proposed that would allow formation evaluation and borehole navigation while drilling in real-time. The savings in drilling/rig time and cost would be substantial. In 2000, Grant Prideco and Novatek formed a joint venture corporation, IntelleServ, to commercialize a high-speed drill pipe telemetry system. In 2001, US Department of Energy’s National Energy Technology Laboratory (NETL) partly funded the venture. The need and uses for this technology, its design, testing and status to date are discussed herein.

Tailor lightweight slurry designs to well conditions and production plans

More than ever before, operators and service companies planning lightweight oil- and gas-well cement jobs are giving attention to casing/cement sheath integrity for the entire life of oil, gas, geothermal and gas-storage wells.


50th Annual ReedHycalog Rig Census

The ReedHycalog rig census has been an industry standard for half a century. When Grant Prideco acquired ReedHycalog last December, it was felt that the industry valued having an annual barometer of the drilling fleet, so the census was reactivated. Because the census was not taken in 2002, an estimate of activity was developed using information supplied by Rig Data. The US rig fleet remains strong, losing just three units since the census was taken two years ago. Drilling activity has fluctuated greatly since 2001’s activity peak. However, fleet utilization still measures a solid 78% according to this year’s data.

Analyzing fractures from seismic for improved drilling success

The Pinedale Anticline in Wyoming, USA, has become an area of significant interest since the recent success of several gas wells completed in its tight sandstone reservoirs. Production from these reservoirs is now possible using new stimulation techniques that were developed in neighboring Jonah field. The best production rates appear to come from reservoirs enhanced by natural fractures. Therefore, a new technique that detects open natural fractures in the reservoir could help the success of future wells. This new technique, AVAZ, uses azimuthal variations in the amplitudes of seismic data, at long shot/receiver offsets, to identify fractures. A modification of this technique has been used on a portion of Veritas’ multi-client 3D survey over the Pinedale anticline to identify the presence of these fractures in the interwell region. Results of this analysis were compared to what is already known about fractures in the reservoirs of the Pinedale anticline.

Petroleum Technology Digest: Integrated rod-pump controller cuts operating costs

Phoenix Hydrocarbons Operating Co. agreed to beta-test the new iBEAM rod-pump controller (RPC) on one of its low-productivity wells in Esperson Dome field near Dayton, Texas. The field has 120 rod-pumped wells that lift fluids from depths of 2,000 to 4,000 ft. Sixty of these wells operate on timers, and one is controlled by an iBeam RPC, Fig. 1. This well produces 6 bopd with 50% water cut. The 2-in. by 1.5-in. by 10-ft THD pump produces 22°API gravity oil from a depth of 2,300 ft.

Progressive seismic data mining for reservoir characterization

Seismic interpreters are required to work with larger and larger seismic volumes as the amount of seismic data acquired and processed increases. Rapid advances in seismic-attribute methods further increase data-set sizes by providing many coincident seismic-attribute volumes for each data set. These exponential increases in available data represent huge data management and data interpretation challenges to our industry.

Understanding compact pipe connection technology benefits

How lighter-weight, smaller-diameter bolted flanges with internal sealing features offer advantages over conventional flange systems


Companies in the news

New literature

A brochure from Enerflex Systems Ltd. describes the company’s products and services for the global oil and gas production industry. Included are service, parts and re-engineering of existing compression and power-generation packages; design and packaging of new compression equipment to any standard; a variety of power-generating equipment designs; hydrocarbon production and processing facilities; instrumentation and controls; production equipment rental and leasing; flare systems and combustion equipment; and a training facility related to gas compression equipment and service.

New products

AnTech Oilfield Software, a division of AnTech Ltd, introduced a major upgrade to StringView Millennium, it’s well-visualization software program, that can interface with existing IT programs to produce custom reports and well diagrams of a broad range of wells. The program has been substantially improved, offering a number of new capabilities: integrated tool editing, making it possible for users to create custom icons from scratch or by modifying an existing tool from the library; new parametric search facility, which allows users to search for tools using any properties, saving time and effort; improved user interface, making it easier to access the specific activities the user carries out most often; increased printing speed; and snap-to-grid capability so that placement of tool strings is more precise. Overall, the new StringView Millennium offers greater speed and an expanded range of capabilities, while retaining its ability to embed seamlessly into any existing IT application. Data may be extracted directly from an existing database and combined with the component library to produce a well diagram, complete with logos and data tables reflecting the user’s designated company product. User-defined parameters may be added to contain existing data in any style, and the well diagram may be modified according to that data.

People in industry

UWG Group appointed Alan MacKenzie Engineering Services business manager. MacKenzie, who will be based in Norwich, joins the company from Baker Oil Tools, where he held positions in design engineering, international operations and marketing. Most recently, MacKenzie was involved in intelligent well design for Eastern Hemisphere applications. He has been awarded patents in underbalanced completions, multilateral drilling and completions and in expandable technologies.


Drilling advances

Rotary steerable slimhole system. Schlumberger Oilfield Services has signed a contract with Shell UK Ltd. and BP Exploration Operating Co. Ltd. to develop a rotary steerable system for slimhole drilling and through-tubing rotary drilling (TTRD) applications. It says that, with the push to maximize production from mature reservoirs where drilling targets are becoming smaller and smaller, it had to find a way of reducing drilling costs and sidetracking from an existing but obsolete well – TTRD is a good way of doing that.

Editorial Comment

Everything’s possible, even independence from OPEC. The other day I was looking at the old newspaper that I’d saved from July 20, 1969. I remember thinking how odd it was that that extraordinary day is not remembered.

International Politics

Politics plague Venezuelan E&P. Local businessmen accuse President Hugo Chávez of retaliating against companies and individuals at PDVSA who participated in last year’s strikes. Reportedly, PDVSA is denying new contracts to these firms and refusing to extend existing deals. PDVSA even denied its own gas compressor company, Energy Dynamics de Venezuela, contracts during August. Political uncertainty has not deterred investors from the gas sector. Local firm Vinncler and 12 multinationals have agreed to bid on developing Blocks 3 and 5 of the offshore Deltana Platform. The energy ministry will set each block’s base amount and then issue licenses to the highest bidders.

What's new in production

Oil company technical cooperatives. Two major operators, ChevronTexaco and Shell, are joining with outside research organizations to help supply needed new technologies. In California, the University of Southern California (USC) and Chevron Texaco (CT) plan to establish the new Center of Interactive Smart Oilfield Technologies (CiSoft) at USC to develop advanced technologies to improve oil and gas exploration and production efficiency. CT will provide R&D funding to establish the center, which will draw upon faculty expertise and resources within the USC School of Engineering’s Information Sciences Institute, the Integrated Media System Center and the Petroleum Engineering Program.

What's new in exploration

Bigger than they thought. Petrobras’ largest gas discovery, made last April, originally had estimated reserves of 2.5 Tcf. Further drilling has revised those estimates dramatically upward, to 14.7 Tcf, plus an undisclosed but significant amount of condensate. Since this report comes from newspapers, plus the fact that structures this large cannot reasonably prove up that much gas with a couple wells, be cautious in accepting this as proved, recoverable gas reserves. The upward revision, if it holds, means that Brazil’s gas reserves could nearly triple.

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