GEOSCIENCES

Gene Kliewer • Houston 

With the Offshore Technology Conference upon us and bringing new technologies to the fore, it is time to look at some of the most recent developments in the geology and geophysics world.

A move by Saudi Aramco gives it a US patent on a method to improve geoseismic data interpretation with a new algorithm that Aramco says minimizes distortion during processing. According to the patent, the method gives more accurate gradients that were possible before, especially with the volume of data coming in for interpretation these days.

"A few digital formulations describing the gradient operator exist in the scientific community and in the industry," says geological specialist Yuchun E. Wang, one of the inventors, "but, they all introduce distortion in varying degrees and adversely affect the bottom-line quality."

"Our invention produces the least amount of inaccuracy when applying it to seismic data," says co-inventor Mohammed N. Faraj of Geophysical Technical Services. "It is almost purely isotropic, meaning that it sees the same thing irrespective of the angle it's looking from."

The invention, holding U.S. Patent No. 7,653,258, is software formulated as an algorithm and encoded in the form of a computer subroutine.

RokDoc-Well Tie 1.0 from Ikon Science is designed to simplify the job of connecting well data and seismic data. The module is workflow driven, says Ikon, and incorporates cascaded workflows enabling users to see the effects on the tie-in of changes in any part of the process including wavelet estimation, and stretch and squeeze log editing.

The workflow-driven approach has user help and guidance. For example, unrealistic changes in interval velocity as a result of trying to stretch and squeeze data are highlighted automatically to enforce the laws of physics on system users. The program is available as a plug-in to Petrel.

"The science of tying well data to seismic is recognized by everyone as a fundamental task that all interpreters need to do," says Martyn Millwood Hargrave, CEO of Ikon. "This …package is aimed at geoscientists who do not need to be familiar with RokDoc or rock physics but who need a fast, accurate, and easy-to-use way to ensure that their well data and seismic data are accurately tied."

Elsewhere, Statoil chooses Ikon Science to implement bespoke exploration and reservoir geophysics methodology into RokDoc.

A selection of methods published by Statoil and used in Statoil's quantitative seismic analysis will complement the existing functionality in RokDoc modules. In addition, the project also allows Statoil to link proprietary code to RokDoc using the newly released RokDoc external interface.

"Statoil has always been a world leader in the field of rock physics and 4D seismic, and we are very excited to be working with them to implement this leading edge technology into the RokDoc system," says Hargrave. "The external interface, which was developed in collaboration with Statoil, will form a key part of the project as it allows companies to deploy proprietary technology throughout their organizations using the familiar RokDoc user interface."

Stingray Geophysical Ltd. has a new approach to integrated seismic permanent reservoir monitoring (PRM). In addition to maintaining a core team of experts with a range of skills, Stingray draws upon its network of trusted partners worldwide to assemble purpose-built teams with the key competences required to meet the specific challenges of each project and deliver complete customer solutions, according to Stingray.

Clair field has a complex seabed environment, with geophysical and field infrastructure constraints to the installation of permanent seabed systems. Stingray and its partners were asked to identify how high data quality might be obtained in such conditions in a reasonable time using low-risk installations. To reduce the need for power and space offshore, the study considered how to control and monitor subsea equipment without recording equipment on the platform.

In the other study, on the Schiehallion field, surface seismic data acquisition is made difficult by an FPSO, shuttle tankers, drilling rigs, and construction vessels. This, coupled with the congested seabed and the probability of field expansion, creates a complex environment for a permanent array. The study examined using FosarDeep concepts to introduce a PRM system under the FPSO and in obstructed wellhead areas.

Spectrum has upgraded its seismic data processing technology with Tsunami's 3D anisotropic Kirchhoff Pre-Stack Depth Migration (PSDM) and 3D grid tomography model building software. The new software enhances seismic data processing in response to the demand for 3D pre-stack depth imaging services.

The Tsunami software suite will be available to Spectrum's seismic processors through a multi-core license.

A 3D reprocessing and imaging project in the eastern Mediterranean is one of the first to use the full capabilities of the software. Spectrum will reprocess and depth image the project.

Spectrum also uses the new 3D Kirchhoff PSDM software to process seismic surveys from India and the Middle East, and multi client surveys from the Gulf of Mexico and India.

Schlumberger has acquired Nexus Geosciences Inc., a provider of integrated seismic software and services for rapid imaging, modeling, and interpretation. It will become part of the WesternGeco business unit.

Nexus has proprietary technologies for fast imaging and modeling, enabling oil and gas companies to rapidly build, update, and validate velocity models.

"Our customers are exploring in areas of increasing geological complexity while under considerable time pressures," says Maurice Nessim, vice president of WesternGeco GeoSolutions. "The combination of Nexus proven imaging and modeling expertise with WesternGeco advanced imaging solutions and global reach will allow us to help our customers meet these challenges more effectively."

CGGVeritas owned Hampson-Russell Software & Services has sold full commercial rights of its GLI3D refraction statics software to GeoTomo Llc. GeoTomo creates and distributes surface and downhole seismic modeling and imaging software products.

"The decision to sell GLI3D ownership further supports the focus of Hampson-Russell Software & Services on our Reservoir Characterization suite of software products," says Dan Hampson, president of Hampson-Russell GP Inc. "It is also clear that GLI3D is an excellent match with the strategy and direction of GeoTomo."

Jie Zhang, president of GeoTomo, says: "GLI3D is an industry-standard software solution for refraction statics problems. With the inclusion of GLI3D in the GeoTomo near-surface solution package, TomoPlus, GeoTomo is able to offer users a complete suite of near-surface solutions in addition to the current high-end traveltime and waveform tomography technologies in TomoPlus."

Statoil has signed a three-year frame agreement with Aker Solutions for subsurface consultancy services, starting this past March with options to for two one-year extensions.

The services relate to Statoil's worldwide production/exploration geology and reservoir technology.

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