Schlumberger Technology Corporation

Services Petroliers Schlumberger

Christopher Edward Morriss

Koji Ito

Shahzad Asif

Roger Griffiths

John C Rasmus

Jacques R Tabanou

Robert Freedman

Keli Sun

Steve F Crary

David Maggs

Charles Flaum

Denis Heliot

Jaideva C Goswami

Austin Boyd

Sushil Shetty

John E Smaardyk

Don Thornton Macune

Joseph M Steiner, Jr

Richard W Oldigs

Hui Xie

Jason P MacInnis

Joan Abadie

Mohammad Taghi Salehi

Vittorio Picco

Adrien Chassard

A method, apparatus, and program product utilize a buffer defined relative to a wellbore trajectory to generate a work zone around a wellbore for use in connection with formation modeling. In some embodiments, for example, a closed curve such as a non-rectangular, polygonal work zone may be defined around a wellbore based upon a buffer that extends generally transverse to the trajectory of a length of a wellbore a predetermined distance. In addition, boundaries may be defined in a work zone to effectively split the work zone into multiple closed curves or polygons in response to user editing, e.g., to create one or more subsurface layers in the work zone. In such instances, points defining a subsurface layer may be shared by adjacent layers such that editing of such points will affect each of the layers sharing such points.

Local layer geometry engine with work zone generated from buffer defined relative to a wellbore trajectory

A method for automatic interpretation of bulls-eye and sinusoidal features observed in LWD images is disclosed. In some embodiments, the method includes an automatic workflow for extracting smooth contours from images that demarcate boundaries of structural features, followed by projection of the contours to three-dimensional (3D) point clouds in the well coordinate system for structural interpretation. The method may characterize both sinusoidal features and bulls-eye features, taking into account variations of formation dip/azimuth, or well inclination/azimuth, on the topology of a structural feature. The disclosed method may be sufficiently fast for use in real-time analysis and interpretation, or to provide constraints for physics-based data inversion processing.

Automatic method for three-dimensional structural interpretation of borehole images acquired in high-angle and horizontal wells

A method for transforming a 2D or 3D earth volume geometry into a 1D earth volume geometry includes performing a measurement using the measurement sensor in a wellbore. A layer boundary in the 2D or 3D earth volume geometry that is nearest to the measurement sensor is identified. A vector from the measurement sensor is generated toward the nearest layer boundary. A first intersection is identified between the vector and the nearest layer boundary, and a second intersection is identified between the vector and another layer boundary. Simulated boundaries that extend through the first and second intersections and are perpendicular to the vector are generated. The 1D earth volume geometry that is bounded by the first and second intersections is identified. A property value is extracted from the 2D or 3D earth volume geometry between the first and second intersections. The property value is assigned to the 1D earth geometry.

Method for determining petrophysical properties from logging measurements

Methods, computer-readable media, and systems are disclosed for applying 1D processing in a non-1D formation. In some embodiments, a 3D model or curtain section of a subsurface earth formation may be obtained. A processing window within the 3D model or curtain that is suitable for 1D inversion processing is determined, and a local 1D model for the processing window is built. A 1D inversion is performed on the local 1D model, and inverted formation parameters are used to update the 3D model or curtain section.

Methods, computer-readable media, and systems for applying 1-dimensional (1D) processing in a non-1D formation

Embodiments set forth in this disclosure providing techniques for determining formation parameters, such as horizontal resistivity (Rh), vertical resistivity (Rv), and dip, in high angle and horizontal wells using non-directional resistivity measurements. For example, a method is provided that may include using an electromagnetic logging tool to acquire non-directional resistivity measurements in a wellbore of a high angle or horizontal well. The method may also include defining a processing window that corresponds to a measurement point of the electromagnetic logging tool along a well trajectory that intersects a at least one bed boundary between two layers of a subsurface formation. The method may also include defining a formation structure and defining an initial set of formation parameters for each layer in the formation structure. Furthermore, the method may include inverting the formation parameters for each layer.

Method and apparatus for determining formation properties using non-directional electromagnetic measurements in high angle or horizontal wells

A logging-while-drilling tool is adapted for incorporation with a drill string having a longitudinal axis. The drill string is further adapted for drilling a wellbore penetrating a geological formation. The drilling tool includes a tool body having a central axis disposed in parallel relation with the longitudinal axis of the drill string and an external, circumferential surface spaced radially outward from the central axis. The tool also includes a measurement apparatus for measuring resistivity of a borehole fluid in the wellbore. The measurement apparatus has an electrode array including a current emitting electrode disposed on the circumferential surface. The current emitting electrode is adapted to emit current into a target region of the wellbore spaced laterally between the circumferential surface and the walls of the wellbore. Further, a current receiving electrode is disposed on the circumferential surface and spaced apart from the current emitting electrode. The current receiving electrode is adapted to receive current propagated from the current emitting electrode into the target region. The electrode array occupies an arcuate section of the circumferential surface that extends less than about 180&#xb0; about the central axis.

System, apparatus, and method of conducting borehole resistivity measurements

A method for determining a formation dip angle including extracting features from an acquired well log to obtain a set of features, validating the set of features to obtain a subset of features, generating a layered model using the subset of features, and generating a synthetic log using the layered model and a forward model.

Method and apparatus for determining regional dip properties

A method and apparatus for determining gas corrected porosity using nuclear magnetic resonance (NMR) and density measurements is disclosed. The total porosity (TCMR) or an earth formation is determined using an NMR tool. A log output is generated that indicates the density of the formation. The density porosity of the formation is determined from the log output. The difference between the TCMR-density porosity log accurately indicates the presence of gas. A gas corrected porosity, .phi., and gas saturation, S.sub.g, are determined based upon the density porosity and TCMR.

Method and apparatus for measuring total nuclear magnetic resonance

When a pulsed nuclear magnetic resonance (NMR) well logging tool is traversing a wellbore, a NMR well logging method includes magnetizing the hydrogen nuclei in a formation traversed by the tool with a static magnetic field, waiting for a first period of time W.sub.1, energizing the formation with oscillating RF pulses, collecting a first plurality of spin echo signals, waiting a second period of time W.sub.2 which is different from the first period of time W.sub.1, energizing the formation with oscillating RF pulses, collecting a second plurality of spin echo signals, waiting a third period of time W.sub.3 which is different from both the second period of time W.sub.2 and the first period of time W.sub.1, energizing the formation with oscillating RF pulses, collecting a third plurality of spin echo signals, etc. The first, second and third, etc. plurality of spin echo signals corresponding to the different wait times are input to a signal processing apparatus disposed in the tool. Window sums of spin-echo signals are computed and transmitted uphole to a surface oriented signal processing apparatus. In response to the window sums, the surface signal processing apparatus determines an apparent formation T.sub.2 -distribution for each wait time in the multi-wait time pulse sequence. The apparent T.sub.2 -distributions are used to construct a cost function. When the cost function is minimized, the surface oriented signal processing apparatus determines estimates of the true T.sub.1 /T.sub.2 ratios and intrinsic T.sub.2 -distributions of the formations being logged. The surface signal processing apparatus uses the new T.sub.2 -distribution to generate new, more accurate, output record medium.

Apparatus including multi-wait time pulsed NMR logging method for

NMR logging apparatus is provided which produces a strong, static and homogeneous magnetic field B.sub.0 in a Volume of an adjacent formation on one side of the tool to measure nuclear magnetic resonance characteristics thereof at two different depths of investigations. In the preferred embodiment, the tool has an RF antenna mounted on the outside of the metal body of the tool, directing focused oscillating magnetic fields B.sub.1 at said Volume to polarize or tip the magnetic moments of hydrogen nuclei of fluids within rock pores. The same antenna can be used to receive signals of proton precession in the Volume of interest immediately after transmission of the RF polarizing field B.sub.1. One of the NMR readings is employed to compensate for inaccuracies in the other NMR reading to provide an overall improved NMR log.

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Sugar Land, TX, United States of America

Christopher Edward Morriss