Abstract: A first NMR echo train is acquired with a single TE. A second NMR echo train is acquired with a first portion having the same TE and the second portion having a longer TE. When measurements are made with a low magnetic field gradient, processing the two echo trains can be used to determine gas in the formation.

Abstract: A C/O ratio is determined using measurements of inelastically scattered gamma rays with a pulsed neutron source. Combined with look-up tables, the C/O measurement is used as an indicator of formation fluid influx into wellbore such as gas kick.

Abstract: Pulse sequences are applied to a fluid in an earth formation in a static magnetic field and NMR spin echo signals are obtained. The signals are inverted to give T2 distributions at a plurality of depths. Similarities between logs of the T2 bins with resistivity and/or gamma ray logs are used to identify and subtract contributions to the NMR signal from oil. having internal gradients. From the received signals, relaxation and diffusion characteristics of the fluid are determined. The determination takes into account the internal field gradients. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. 37 CFR 1.72(b).

Abstract: The average current at a plurality of measure electrodes of a resistivity imaging tool is determined and subtracted from the individual measure currents to give a resistivity image with improved dynamic range.

Abstract: Reactive phosphorus species can be removed or transferred from a hydrocarbon phase to a water phase in an emulsion breaking process by using a composition that contains water-soluble hydroxyacids. Suitable water-soluble hydroxyacids include, but are not necessarily limited to glycolic acid, gluconic acid, C2-C4 alpha-hydroxy acids, poly-hydroxy carboxylic acids, thioglycolic acid, chloroacetic acid, polymeric forms of the above hydroxyacids, poly-glycolic esters, glycolate ethers, and ammonium salt and alkali metal salts of these hydroxyacids, and mixtures thereof. The composition may optionally include a mineral acid to reduce the pH of the desalter wash water. A solvent may be optionally included in the composition. The invention permits transfer of reactive phosphorus species into the aqueous phase with little or no hydrocarbon phase undercarry into the aqueous phase. The composition is particularly useful in treating crude oil emulsions, and in removing calcium and other metals therefrom.

Abstract: A casing inspection device with magnets and a multi-component flux sensors. The multicomponent sensor enables better definition of the size of defects, particularly in the azimuthal direction.

Abstract: Methods and systems are provided for displaying and forecasting the lithology and wellbore conditions to be encountered while conducting drill string operations are conducted in a wellbore. A method and system is described for predicting and modeling lithology while operating a drill string in a wellbore, comprising: developing a 3-D lithological model of a subsurface area; projecting a well path through said subsurface area; determining an open cylinder lithology display of said projected well path; and recording said determined open cylinder display. The open cylinder lithology display (the Predictive Stratigraphy Image) may be displayed with geological or structural cross-sections to compare the well path and the predicted well path, with the actual subsurface environment. Data acquired during drilling operations can be used in real time to update the model or the Predictive Stratigraphy Image, and the results compared with Predictive Image Logs and other wellbore images and data.

Abstract: Measurements made by a multi-component induction logging tool are corrected for tool eccentricity in a deviated borehole. The eccentricity angle is determined from single frequency skin-effect corrected data and is then used to correct multifrequency data. Multifrequency focusing is then applied to the corrected multifrequency data. An inversion is then used to recover formation resistivity and relative dip and azimuth of the borehole.

Abstract: Pellets can be injected into oil and gas production equipment that may contain stagnant or slow moving system fluids to treat the stagnant or slow moving system fluids to prevent conditions such as corrosion. The pellets have a density such that they may be moved through the equipment by system fluids passing therethrough. When the pellets come into contact with the stagnant or slow moving system fluids, sufficient pellets enter the stagnant or slow moving system fluids to treat it. It is emphasized that this abstract is provided to comply with the rules requiring an abstract which will allow a searcher or other reader to quickly ascertain the subject matter of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Measurements are made continuously with a seismic while drilling (SWD) system and the measured data are stored in a working memory of a downhole processor along with quality control (QC) measurements. The QC data are analyzed and based on the analysis, portions of the data in working memory are recorded in permanent memory for retrieval. Alternatively, QC measurements are made substantially continuously predictions are made when data quality for SWD measurements are likely to be good. Recording of SWD data are then started based on the prediction.

Abstract: An actuator operatively coupled to a wellbore tool is activated upon receiving fluid that a predetermined applied pressure. When the fluid string reaches the predetermined applied pressure, the actuator undertakes a specified action such as longitudinal movement, rotation, expansion, etc. that actuates or operates the wellbore tool. Premature actuation of the wellbore tool is prevented by applying a resistive force to the actuator that, alone or in cooperation with another mechanism, arrests movement of the actuator. This resistive force is generated by applied pressure of the fluid in the work string.

Abstract: A flow conduit may have at least one orifice is in the vicinity of a flow source. The source is at least partially covered (and flow blocked by) an optional temporary coating or barrier. The flow pathway between the orifice and the source is temporarily blocked with a degradable material or barrier. The material disintegrates (e.g. under the influence of time or temperature) to optionally produce a product that removes the temporary coating in the area adjacent the barrier. The method is useful in one non-limiting context of recovering hydrocarbons where the flow conduit is the casing or liner of the well and the flow source is a subterranean reservoir where the temporary coating is a filter cake.

Abstract: An apparatus for controlling a flow of a fluid into a wellbore tubular includes a flow path associated with a production control device; an occlusion member positioned along the flow path that selectively occludes the flow path, and a reactive media disposed along the flow path that change a pressure differential across at least a portion of the flow path by interacting with a selected fluid. The reactive media may be a water swellable material or an oil swellable material. The reactive media may be selected or formulated to change a parameter related to the flow path. Illustrative parameters include, but are not limited to, (i) permeability, (ii) tortuosity, (iii) turbulence, (iv) viscosity, and (v) cross-sectional flow area.

Abstract: A multicomponent induction logging tool is used on a MWD bottomhole assembly. Multifrequency focusing that accounts for the finite, nonzero, conductivity of the mandrel is applied. Using separation of modes, the principal components and relative dip angles in an earth formation are determined. The results are used for reservoir navigation in an earth formation.

Abstract: An apparatus and a method for migration of three components, 3-Dimensions seismic (3-C, 3-D) data acquired by down-hole receivers and surface seismic sources. This method utilizes full 3 components reflection wave field. It uses a dynamic, vector energy mapping method to image a reflection position and maps each time sample only to its reflected image point. Therefore, this method reduces unwanted data smearing and false mirror images. This method overcomes the weakness of using only a single component trace or pre-rotated three-component traces in the 1-C or 3-C 3-D VSP migration and produces better 3-D image.

Abstract: A photodiode whose long-wavelength cutoff is in the short-wavelength range (preferably, between ultraviolet and yellowish-green) having reduced temperature sensitivity is used in downhole applications. It may be matched with scintillation devices having an output matched to the response curve of the photodiode for use with nuclear logging devices. The photodiode may also be used in gyroscopes in which light from an LED matched to the photodiode is reflected from a spinning mass.

Abstract: A sampling tool for retrieving one or more samples from a wellbore drilled in a subterranean formation includes a coring device retrieving a core from a wellbore wall, wellbore isolation devices that isolate an annular region proximate to the coring device; and a flow device that flows fluid out of the isolated region. During operation, the sampling tool is positioned adjacent a formation of interest. The isolation device is activated to isolate an annular region proximate to the sampling tool. Decentralizing arms can be used to position the coring device next to the wellbore wall. Thereafter, the flow device flows fluid out of the isolated annular region. When the isolated region includes mostly formation fluid, the coring device is activated to retrieve a core from a wall of the wellbore in the isolated annular region and store it in formation fluid.

Abstract: In a multicomponent logging tool, a coil is electrically isolated by open circuiting another, substantially orthogonal coil.

Abstract: Many reservoirs of interest include heavy oil. In such reservoirs, partly at normal temperatures, many instruments commonly used for formation evaluation may not be able to distinguish between heavy oil and bound water in the formation. Passive or active heating is used to elevate the temperature of the fluids in the formation. At elevated temperatures, distinguishing between heavy oil and bound water is easier. Of particular interest is the increase in the resolvability of the transverse relaxation time T2 of NMR spin echo measurements. Additionally, the dielectric constant and the loss tangents of water and heavy oil show different temperature and frequency dependence.

Abstract: A walkaway VSP survey is carried out with receivers located in a borehole near the base salt. Reflection tomographic inversion of data from the walkaway VSP is used to derive a velocity model for the subsurface and may be used for imaging of sub-salt reflections.