Schlumberger Limited is the world's largest oilfield services company. Schlumberger employs approximately 120,000 peoplerepresenting more than 140 nationalities working in more than 85 countries. Its principal offices are in Houston, Paris, London, and the Hague. Wikipedia.
Saudi Aramco and Schlumberger | Date: 2016-12-13
A method and apparatus for a bimodal stimulation composition for removal of thickness of a filter cake while minimizing fluid loss is provided. The bimodal stimulation composition includes water, a salt, an acid, and a viscoelastic surfactant.
Schlumberger | Date: 2016-08-25
A rotary controlled system includes first and second alternators electrically connected to one another via a DC voltage bus. The alternators may optionally be further mechanically connected to one another via corresponding rotationally coupled components (such as rotationally coupled stators). A first field oriented controller is electrically connected with the first alternator and configured to cause the first alternator to provide a constant DC voltage to the voltage bus. A second field oriented controller is electrically connected with the second alternator and configured to receive electrical power from the voltage bus and cause the second alternator to provide servo angular position control of the rotationally coupled components. The system may be employed in a downhole rotary steerable tool to provide servo angular position control of a roll stabilized housing.
Schlumberger | Date: 2017-04-05
Systems, methods, and computer-readable media for evaluating annular material using beamforming from acoustic arrays are provided. A logging tool may include one or more acoustic phased arrays, such as one or more transmitter arrays and one or more receiver arrays each having multiple transducer elements. The acoustic signals may be beamformed by independently pulsing array elements of the arrays to excite and detect desired wave modes in a casing or other material in a well. Parameters of the casing or other material in the well may be determined using the received acoustic signal.
Schlumberger | Date: 2017-03-01
The disclosure relates to a sleeve (200) for fitting around a spooling drum : the sleeve comprises at least a groove (202) for receiving a conveying element to be spooled around the drum, is made of flexible material and is configured so as to be able to take a first configuration in which the sleeve forms a flat sheet, the groove extending in a direction, called spooling direction, and a second configuration in which the sleeve forms a cylinder, with the groove is situated on an external face of the cylinder.
Schlumberger | Date: 2017-04-05
Systems, methods, and computer-readable media for determining shear-wave to compressional-wave velocity ratios in well casings are provided. A logging tool may include one or more acoustic phased arrays, such as one or more transmitter arrays and one or more receiver arrays each having multiple transducer elements. Peak pulse amplitudes may be calculated from received acoustic signals, and the group velocity of the peak mode may be calculated. The peak amplitude from measurements over a suitable incidence angle range may be used to determine the value of the shear-wave to compressional-wave velocity ratio.
Schlumberger | Date: 2017-03-29
Systems and methods are provided for estimating the tool center position of a downhole tool, the geometry of the borehole, and/or a mud parameter based on sensor measurements from the downhole tool, even when the downhole tool center is moving over time. At least one sensor may obtain a set of measurements that relates to distance-to-borehole in a borehole at a number of azimuths. A processor may estimate a set of values defining borehole boundary and a set of positions of a center of the downhole tool in the borehole, at least in part by estimating the borehole boundary based on the set of measurements assuming a previously estimated position of the center of the downhole tool is true and estimating the position of the center of the downhole tool based on the set of measurements assuming a previously estimated borehole boundary is true, and iterating at least until convergence.
Schlumberger | Date: 2017-03-22
Apparatus and methods for assessing contamination of formation fluid. A downhole sampling tool (200) is operated to draw fluid from a subterranean formation into a chamber (336) of the downhole sampling tool (200). The downhole sampling tool is then operated to discharge the fluid from the chamber (336) while monitoring pressure of the fluid and volume of the chamber. Contamination of the discharged fluid is assessed based on the monitored fluid pressure and the monitored chamber volume.
Schlumberger | Date: 2017-01-11
Cement slurry compositions comprising water, portland cement, styrene-butadiene latex and polystyrene sulfonate exhibit improved stability (i.e., lower free fluid values). The slurries may further comprise bentonite, attapulgite, sepiolite, laponite, zeolites, colloidal silica, microsilica or silica fume or combinations thereof. Such compositions may be used for well cementing operations. The operations may be primary cementing or remedial cementing.
Schlumberger | Date: 2017-01-04
A technique facilitates mitigation of shock loads. Subterranean communication systems may comprise components susceptible to various shock loads. A shock mitigation system (30) is physically coupled with the subterranean communication system (28) to mitigate such shock loads. The shock mitigation system (30) comprises components selected to enable reduction of various effects of shock loads, e.g. shock loads resulting from perforating procedures, which could otherwise be detrimental to continued operation of the subterranean communication system.
Annual Review of Analytical Chemistry | Year: 2011
Asphaltenes, the most aromatic of the heaviest components of crude oil, are critical to all aspects of petroleum utilization, including reservoir characterization, production, transportation, refining, upgrading, paving, and coating materials. The asphaltenes, which are solid, have or impart crucial and often deleterious attributes in fluids such as high viscosity, emulsion stability, low distillate yields, and inopportune phase separation. Nevertheless, fundamental uncertainties had precluded a first-principles approach to asphaltenes until now. Recently, asphaltene science has undergone a renaissance; many basic molecular and nanocolloidal properties have been resolved and codified in the modified Yen model (also known as the Yen-Mullins model), thereby enabling predictive asphaltene science. Advances in analytical chemistry, especially mass spectrometry, enable the identification of tens of thousands of distinct chemical species in crude oils and asphaltenes. These and other powerful advances in asphaltene science fall under the banner of petroleomics, which incorporates predictive petroleum science and provides a framework for future developments. Copyright © 2011 by Annual Reviews. All rights reserved.