Schlumberger Technology Corporation

Robert Burridge

Maarten De Hoop

Carl Peter Spencer

Bikash Kumar Sinha

Benoit Couet

Nicholas N Bennett

David J Wilkinson

Naoki Saito

Michael Kane

Methods for optimization of oil well production with deference to reservoir and financial uncertainty include the application of portfolio management theory to associate levels of risk with Net Present Values (NPV) of the amount of oil expected to be extracted from the reservoir. Using the methods of the invention, production parameters such as pumping rates can be chosen to maximize NPV without exceeding a given level of risk, or, for a given level of risk, the minimum guaranteed NPV can be predicted to a 90% probability. An iterative process of generating efficient frontiers for objective functions such as NPV is provided.

Optimization of oil well production with deference to reservoir and financial uncertainty

A method for determining a radial profile of sonic shear velocity of formations surrounding a fluid-containing borehole, including: suspending a logging device in the borehole; transmitting sonic energy from the logging device to establish flexural waves in the formation; receiving sonic energy from the flexural waves and producing, from the received sonic energy, measurement signals at a number of frequencies; determining, at each frequency, the flexural wave velocity in the formation; deriving sonic compressional and shear velocities of the substantially undisturbed formation; deriving sonic compressional velocity of the borehole fluid; and determining the radial profile of sonic shear velocity from the derived compressional and shear velocities of the substantially undisturbed formation, the derived compressional velocity of the borehole fluid, and the flexural wave velocities.

Sonic well logging for radial profiling

A borehole image interpretation method that utilizes a Hough transform technique is described. The method can detect planar structures such as fractures and formation beddings in the borehole, as well as geometric patterns such as elliptical vugs.

Method of determining dips and azimuths of fractures from borehole images

A method for determining the anisotropic properties of an unknown earth formation by means of seismic exploration includes generating seismic signals for propagation through the unknown formation. A range of seismic data samples generated by the propagation of the signals through the unknown formation is detected, and the detected samples are affected by the anisotropic properties of the unknown formation. A group of postulated anisotropic properties which would cause known perturbations in seismic signals are selected for the unknown formation. The detected range of seismic data samples from the unknown earth formation is compared with estimated ranges that could have been produced by seismic signals propagating through earth formations made up with differing weighting of components of the postulated anisotropic properties. The estimated range that best matches the detected range is identified, and the related weighted components of the postulated anisotropic properties are attributed to the unknown earth formation.

Method of processing seismic data

A method is provided for processing seismic data samples obtained from seismic signals propagating in an anisotropic medium. The data samples are associated with scattering angles and azimuth at each migration dip at each image point of the medium. An inverse operator is then applied to the samples so as to provide intermediate anisotropic elastic parameter combinations for each migration dip at each point of the medium. The inverse operator comprises an inverse of a scattering function for variations in elastic parameters from a reference medium against scattering angle and migration dip. The intermediate anisotropic elastic parameter combinations are then migrated to their proper locations.

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Boston, MA, United States of America

Robert Burridge