Westerngeco L.l.p.

Other

Schlumberger Technology Corporation

Geco Technology B.v.

Philip Christie

Nicolas Goujon

Rune Sindre Voldsbekk

Johan Fredrik Naes

James Martin

Benjamin Peter Jeffryes

Richard Timothy Coates

Iain Michael Cooper

John Mervyn Cook

Paul Simon Hammond

Paul Bolchover

Anthony D Curtis

David Edward Nichols

Zoe Lunnon

Zoë Lunnon

William Li-Tien Wang

A method of processing seismic data is provided in the seismic data is acquired at a plurality of locations and the method comprises interpolating and/or extrapolating the seismic data, thereby to estimate seismic data at a target location different from the plurality of locations. The interpolating and/or extrapolating the seismic data is performed in a polar co-ordinate system. The method may provide for, among other things, accuracy of estimation; particularly at short offsets from the seismic source. The polar co-ordinate system used may be chosen to approximate the seismic wavefront in an earth model, for example in an earth model in which properties vary only with depth.

Interpolation and/or extrapolation of seismic data

A method of filtering seismic signals is described using the steps of obtaining the seismic signals generated by activating a seismic source and recording signals emanating from the source at one or more receivers; defining a source signature deconvolution filter to filter the seismic signal, wherein the filter is scaled by a frequency-dependent term based on an estimate of the signal-to-noise (S/N) based on the spectral power of a signal common to a suite of angle-dependent far-field signatures normalized by the total spectral power of the signatures within the angular suite and performing a source signature deconvolution using the source signature deconvolution filter.

Source signature deconvolution method

A method of performing a seismic survey of a hydrocarbon reservoir in the earth formations beneath a body of water includes deploying a seismic cable from a drum carried by a remotely operated vehicle on the seabed. The cable is deployed into a lined trench, which is formed either concurrently with cable deployment or during a previous survey, to ensure good repeatability of successive surveys of the reservoir, in order to enable changes in characteristics of the reservoir, eg due to depletion, to be monitored.

Marine seismic surveying

A method of processing data sequences obtained at substantially the same time at locations spatially separated from one another is disclosed. A sequence indicative of a measure of spread of the data sequences or of selected data sequences is determined. A common signal data sequence may also be determined from the (selected) data sequences. The measure of spread of the data sequences is preferably normalized, for example relative to the absolute value of the common signal data sequence. The measure of spread is a measure of the noise to signal ratio in the initially-obtained data sequences. It may be used to control the parameters of other processing steps performed on the data sequences. Alternatively or additionally, the measure of spread may be output, for example for monitoring by an observer. The method can be applied to the processing of seismic data obtained using a single sensor seismic data acquisition system.

Method of processing data

The present invention provides methods and systems for making measurements associated with a rock formation including a main borehole, a microborehole extending from the main borehole into the rock formation, and one or more sensing devices positioned and arranged to make a measurement at measurement zones being located in the microborehole. A packer can also be installed in the microborehole dimensioned and arranged to hydraulically isolate the measurement zones from conditions present in other parts of the microborehole and/or main borehole. Methods and systems are also provided for taking fluid samples and injecting fluid tracers in a microborehole.

System and method for installation and use of devices in microboreholes

A method of performing a seismic survey of earth formations beneath a body of water is disclosed. The method includes: (a) deploying a seismic cable having a plurality of seismic sensors distributed therealong in close proxmity to elongate locating means provided at the bottom of the body of water; (b) operating an acoustic source in the body of water to produce seismic signals which enter the formations; (c) detecting seismic signals which return from the formations with said sensors; and (d) removing the seismic cable from the bottom of the body of water.

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Fen Drayton, United Kingdom

Philip Christie