Bp Corporation North America Inc.

Schlumberger Technology Corporation

Allan A Ross

Raymond Lee Abma

Matthew R Hackworth

Lance I Fielder

Kevin J Forbes

Nihat Ovutmen

Joseph Anthony Dellinger

John Theodore Etgen

Graham Openshaw

Andrew James Brenders

Michael Pfister

Raymond Abma

A technique for use in geophysical surveying acquires seismic data at low seismic frequencies to generate better starting models for subsurface attributes rather than enhancing the bandwidth of airguns for broadband imaging as in conventional practice.

Seismic acquisition method and apparatus

According to an embodiment, there is provided a system and method of collecting seismic data using a predetermined pattern of source activations that is intended to control the properties of the resulting seismic signal. One embodiment utilizes a seismic source array (or, more generally, any collection of controllable sources) to create a series of spaced apart in time source activations, with the spacing and number of such activations being used to shape the resulting signal. In one method of building sweeps, the guns are fired at an increasing rate (decreasing time separation) as time goes by. Other patterns may be generated by decreasing the firing rate as time goes by, or some combination of the foregoing. In an embodiment, the rate of the increase or decrease in the firing rate will change from pattern to pattern.

Analytically generated shooting schedules for use with patterned and simultaneous source acquisition

So-called 'Popcorn shooting', and especially continuous Popcorn shooting, combined with simultaneous source shooting allows considerable flexibility in producing high-resolution data and in creating source arrays. Using a combination of simultaneous source de-blending and Popcorn reconstruction it is possible to construct using post acquisition processing arrays of any desired length by constructing a popcorn pattern that takes into account the vessel speed and physical arrangement of guns behind the towing vessel.

Spatial sampling improvements and the formation of arrays using popcorn and simultaneous source acquisition

The Monte-Carlo method of generating Popcorn shooting patterns starts with the number and sizes of the guns available and the length in time of the desired Popcorn pattern. The firing times and order of the guns will be randomly perturbed and a large number of Popcorn patterns built. Candidate Popcorn patterns will then be tested against a set of criteria to identify acceptable or the best patterns. These criteria may include limits on maximum peak strength, distinctiveness compared to the other patterns, and the size of the notches and peaks in the spectra.

Seismic source coding, activation, and acquisition

The maximum output of a seismic source array may be reduced by activating the individual seismic sources within these seismic source array in a pattern that is extended in time rather than by the presently employed conventional simultaneous activation of a large number of individual seismic sources. Methods are disclosed which take data shot with patterned sources and may use a sparse inversion method to create data with the about same image quality as that of conventional sources. In this manner the output of the maximum impulse of a seismic source array may be reduced by an amplitude factor of about 10 in the examples shown here, corresponding to a reduction of about 20 dB while maintaining virtually the same seismic image quality. The disclosed methods may be used in combination with any simultaneous sourcing technique. In addition, the disclosed methods may be used with a plurality of source arrays.

Seismic acquisition method and system

A downhole device having an oil/water separator having a well fluid inlet, an oil stream outlet conduit, and a water stream outlet conduit; a removable flow-restrictor located in at least one of the water stream outlet conduit or the oil stream outlet conduit.

Flow control device and method for a downhole oil-water separator

According to a preferred aspect of the instant invention, there is provided a system and method for using satellite communications satellites to control and receive data from a land cableless seismic system. The satellite transmission could transmit control signals (e.g. turn on/off) and receive signals from the remote seismograph units (seismic data, quality control parameters, status, location, etc.) which would subsequently be retransmitted to a processing center or other surface facility.

Satellite communications with cableless seismographs

According to a preferred aspect of the instant invention, there is provided herein a system and method for creating low frequency seismic waves. In brief, the instant invention uses a rotary propeller-type system that has been mounted in, for example, a barge or other marine vessel as a seismic source. In the preferred arrangement, the instant source will generate a seismic signal that has greater low frequency content (e.g., frequencies that are less than about 10 Hz) than has been possible heretofore.

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Houston, TX, United States of America

Allan A Ross