EXPLORATION

Triple over/under seismic acquisition. (WesternGeco) Triple over/under towed-streamer seismic acquisition and processing benefited data acquired in rough sea conditions. The method preserves low frequencies while preserving higher ones. This improves imaging beneath acoustically fast strata such as basalt and some limestones.

The rewards of finding hydrocarbon in the subsalt plays make it attractive for exploration. However, it is a challenging task. The authors explain how to reduce subsurface risk by using a new pore pressure model to increase exploration success, with examples from recent GOM projects.

Best practices in reducing interpretation risk using seismic attributes. (SMT and Fairfield) This article presents a post-stack analysis of 3D seismic data from a field with 15 producing wells in the Gulf of Mexico. The analysis includes the following attributes: amplitude, spectral decomposition, dip of maximum similarity and instantaneous Q, in addition to well log information. The objective is to provide an overview of best practices to determine phase and pay signature within the seismic dataset, reduce the risk of cross-well stratigraphic interpretation, define anomalies by understanding their fundamental cause and reduce structural trapping risk.

 DRILLING

Using depth-of-cut technology (Varel) in PDC bit design to optimize bit performance in directional wells. Drilling simulation software predicted the correct bit design and helped the operator cut drilling time in half. This article tells what is needed from offset data to build the foundation of bit optimization in a difficult drilling environment.

Swellable rubber. (Shell Global Solutions, Swellfix, Statoil) It’s been known for many decades that rubber tends to swell when exposed to oil and gas. Nearly 10 years ago, two companies began working on commercial aspects that exploit this property. Now that the rubber types are known, and testing concluded, the technology has moved into the oil patch and has been applied to isolation with packers, zones and other areas.

Best practices: Cementing across salt formations. (BJ) Almost 60% of the salt zones on the US Gulf Coast remain unexplored. The importance of these salt structures and the potential they represent to future oil production and storage of natural gas resources has become increasingly important, particularly subsalt formations. Cementing oil or gas storage wells carries the risk of cement sheath failure, which can potentially increase operating expenses and decrease company assets. The topic of when to use salt versus non-salt cement slurries has been debated by industry engineers for years. The dynamics of cementing across a salt section and the reasons why salt should or should not be used to obtain the best cement design is the focus of this article.

 INTERNATIONAL STATISTICAL REVIEW/FORECAST

World Oil’s world review statistical tables are meticulously gathered, compiled and qualified. These tables, from our own exclusive surveys, include: oil and gas reserves; wells drilled and wells forecast to be drilled, as well as footage drilled; number of producing wells by various categories, including artificial lift and flowing; all listed by country.

 DEEPWATER TECHNOLOGY

A study of downhole completion failures in subsea wells identified the downhole control line as a principle cause of failures. The cost of recovering equipment and repairing these failures warranted a reliability investigation of downhole control equipment including line clamps, control lines and control line fittings. Authors from Chevron and Halliburton used a system level approach to study the problem and this article explains what that study found.

 AUTOMATION AND CONTROL

Authors from Aspentech and BP tell how good results using sustainable best practices and process optimization were achieved on an offshore platform. In a typical case where the Optimizer was run to predict the maximum attainable oil production for a particular day of interest, it was found that the pressure set points could be optimized to increase production an average of 3%. The performance of the facilities is now much better understood. The Optimizer helps in other functions as well, such as shut-down scenarios, gas injection and varying ambient conditions.

Wireless can be the solution for improving process automation. Authors from Emerson describe how producing platforms and land-based fields are a collection of safety systems, valves, flows, temperatures and pressures that all need to be monitored in real time for optimal control of the field/facility production process. Going wireless can save time and money on installation compared to wired systems, and enable a more mobile workforce that can have constant access to process data wherever they are.

 HEAVY OIL PRODUCTION

Cold heavy oil production with sand. Starting in 2000, Canadian operator Nations Energy initiated Cold Heavy Oil Production with Sand (CHOPS) in Karazhanbas Field (KBM), a giant shallow heavy oil field in western Kazakhstan. PCPs are used to lift the oil, and sand is allowed to enter into perforated zones. CHOPS is an economic success at KBM, allowing recovery factors of 8-15% from zones as thin as 3-10 m, for which thermal technologies are not economically viable. Authors from Nations, Petroleum Geomechanics Inc. and the University of Waterloo describe the geological setting of KBM, reservoir and petrophysical properties, document typical sand-oil-water production, and contrast production behavior with Canadian cases.

 FIELD PRODUCTION SOLUTIONS

Fifty-seven high-permeability wells in Mexico’s offshore Cantarell field were acidized with a novel acid diverter based on an Associative Polymer (AP). The low viscosity of the AP diverting system results in ease of mixing, low-friction pressures and eliminats the need for special manifolding or pump requirements. This AP inherently reduces the formation permeability to water with little or no effect on hydrocarbon permeability. Pemex and Halliburton use field data to show that the AP outperformed other diverters, such as foams and in-situ crosslinked acid.

A novel tool designed to detect and react to drillbit vibration was tested at the Rocky Mountain Oilfield Testing Center (RMOTC). This new tool, the Active Vibration Damper (AVD), developed by APS Technology, Inc., monitors vibrations in the BHA and adjusts the damping coefficient to reduce them. Smith Services is the commercial partner and collaborator in the testing and potential commercialization of the tool. The tests showed the AVD improves drilling economics in two areas: It increases ROP while minimizing vibration.

 DRILL BIT CLASSIFIER

Each year, World Oil publishes this valuable guide for drillbit selection. This comprehensive listing of major manufacturers’ drillbits helps engineers, drilling supervisors and related disciplines that require detailed drillbit information to do their jobs. The guide uses the IADC classification system and shows the substantial changes made from year to year.

 PLUS...

Bonus circulation at SPE and SEG Annual Meetings, and ISA Expo.