Abstract: Estimating a correction factor from logs of compensated thermal neutron porosity measurements, including modeling each measurement of the compensated thermal neutron porosity measurements of the log as resulting from at least: i) a first contribution correlated to an absorbance of a first portion of neutrons produced by irradiation of the volume attributable to interactions in the volume indicative of pore space in the matrix, and ii) a second contribution correlated to an absorbance of a second portion of the neutrons attributable to trace elements of at least one dominant neutron absorber in the formation; iii) a third contribution correlated to an absorbance of a third portion of the neutrons attributable to dry minerals in the matrix other than dominant neutron absorbers; and estimating the second contribution and determining the correction factor from the second contribution; and correcting a compensated thermal neutron porosity measurement using the correction factor.

Abstract: Estimating a correction factor from logs of compensated thermal neutron porosity measurements, including modeling each measurement of the compensated thermal neutron porosity measurements of the log as resulting from at least: i) a first contribution correlated to an absorbance of a first portion of neutrons produced by irradiation of the volume attributable to interactions in the volume indicative of pore space in the matrix, and ii) a second contribution correlated to an absorbance of a second portion of the neutrons attributable to trace elements of at least one dominant neutron absorber in the formation; iii) a third contribution correlated to an absorbance of a third portion of the neutrons attributable to dry minerals in the matrix other than dominant neutron absorbers; and estimating the second contribution and determining the correction factor from the second contribution; and correcting a compensated thermal neutron porosity measurement using the correction factor.

Abstract: Systems, methods and devices for evaluating an earth formation intersected by a borehole. The method includes using a first radiation responsive component to detect gamma rays having an energy below a threshold energy; using a second radiation responsive component configured to detect gamma rays that traverse the first radiation responsive component; generating a reduced-Compton gamma ray spectrum by generating an anticoincidence gamma ray spectrum indicative of the gamma rays detected by the first radiation responsive component and the gamma rays detected by the second radiation responsive component. The anticoincidence gamma ray spectrum represents those gamma rays of the gamma rays detected by the second radiation responsive component that are not detected in coincidence with the gamma rays detected by the first radiation responsive component.

Abstract: Systems, methods and devices for evaluating an earth formation intersected by a borehole. The method includes using a first radiation responsive component to detect gamma rays having an energy below a threshold energy; using a second radiation responsive component configured to detect gamma rays that traverse the first radiation responsive component; generating a reduced-Compton gamma ray spectrum by generating an anticoincidence gamma ray spectrum indicative of the gamma rays detected by the first radiation responsive component and the gamma rays detected by the second radiation responsive component. The anticoincidence gamma ray spectrum represents those gamma rays of the gamma rays detected by the second radiation responsive component that are not detected in coincidence with the gamma rays detected by the first radiation responsive component.

Abstract: Methods, systems and devices for estimating a parameter of interest from a gamma ray spectrum relating to a volume of matter using standard gamma ray spectra from reference samples, wherein there is at least one non-elemental characteristic that is different between the volume and at least one of the reference samples, wherein the non-elemental characteristic difference affects gamma ray interactions. Methods may include deconvolving a gamma ray spectrum obtained from the analysis volume into a plurality of elemental spectral yields, wherein deconvolution includes compensating for effects of the non-elemental characteristic difference. Methods may include using at least one compensation standard spectrum configured to compensate for the effects of the non-elemental characteristic of the at least one of the reference samples.

Abstract: Methods, systems and devices for estimating a parameter of interest from a gamma ray spectrum relating to a volume of matter using standard gamma ray spectra from reference samples, wherein there is at least one non-elemental characteristic that is different between the volume and at least one of the reference samples, wherein the non-elemental characteristic difference affects gamma ray interactions. Methods may include deconvolving a gamma ray spectrum obtained from the analysis volume into a plurality of elemental spectral yields, wherein deconvolution includes compensating for effects of the non-elemental characteristic difference. Methods may include using at least one compensation standard spectrum configured to compensate for the effects of the non-elemental characteristic of the at least one of the reference samples.

Abstract: A method for evaluating an earth formation from a well bore, that includes: collecting at least one of geochemical data, petrophysical data and geomechanical data from a wellbore; and identifying depositional facies of the earth surrounding the wellbore. A computer program product and a system are provided.

Abstract: A method for estimating a lithotype of an earth formation, the method includes: obtaining at least two different energy spectra of radiation received from the earth formation using the logging tool, each energy spectrum having at least one of a natural gamma-ray spectrum, a fast neutron-induced inelastic spectrum, and a thermal neutron induced capture spectrum; establishing at least one geochemically-based constraint related to elemental spectral yields to be determined; determining the elemental spectral yields from the at least two different energy spectra by decomposing the at least two different energy spectra over weighted sum of monoelemental standards wherein at least one weight is constrained by the at least one geochemically-based constraint and each weight represents a proportion of one monoelemental standard; converting the elemental spectral yields to elemental concentrations; and using a classifier to receive the elemental concentrations as input and to provide a lithotype as output.

Abstract: Methods, systems, apparatus and processes for determining the lithology as well as the mineralogy of subterranean formations surrounding a borehole are described. According to the methods and processes, well log data measurements from neutron spectroscopy applications and associated tool response parameters are solved using an artificial intelligence system, such as an expert system, which in turn generates an appropriate discriminator and/or compositional model that estimates both general and specific lithology as well as the mineralogy constraints of the subterranean formation being analyzed. The methods exhibit good elemental correlation between conventional methods of lithology and mineralogy determination, and can provide numerous output data, including grain density and porosity data within zones of the formation.

Abstract: A method for estimating a lithotype of an earth formation, the method includes: obtaining at least two different energy spectra of radiation received from the earth formation using the logging tool, each energy spectrum having at least one of a natural gamma-ray spectrum, a fast neutron-induced inelastic spectrum, and a thermal neutron induced capture spectrum; establishing at least one geochemically-based constraint related to elemental spectral yields to be determined; determining the elemental spectral yields from the at least two different energy spectra by decomposing the at least two different energy spectra over weighted sum of monoelemental standards wherein at least one weight is constrained by the at least one geochemically-based constraint and each weight represents a proportion of one monoelemental standard; converting the elemental spectral yields to elemental concentrations; and using a classifier to receive the elemental concentrations as input and to provide a lithotype as output.

Abstract: Elemental analysis of an earth formation is obtained using measurements from a gamma ray logging tool. From the elemental analysis, an estimate of the Calcium, Magnesium and Carbon content of the formation is determined. The amount of organic carbon in the formation is estimated from the total Carbon content and the inorganic carbon associated with minerals in the formation. An indication of source rock may be obtained from the Th/U ratio.

Abstract: A method for evaluating an earth formation from a well bore, that includes: collecting at least one of geochemical data, petrophysical data and geomechanical data from a wellbore; and identifying depositional facies of the earth surrounding the wellbore. A computer program product and a system are provided.

Abstract: A method for inhibiting the formation of gas hydrates in a petroleum fluid having hydrate-forming constituents is claimed. More specifically, the method can be used to treat a petroleum fluid, such as natural gas conveyed in a pipe, to inhibit the formation of a hydrate flow restriction in the pipe. The preferred hydrate inhibitors used for practicing the method comprise substantially water soluble homopolymers and copolymers of isopropylmethacrylamide derivatives which have a bimodal molecular weight distribution.

Abstract: A low value of Th/U ratio as determined from natural gamma radiation is indicative of deepwater sedimentation. This, together with estimates of total organic carbon from pulsed neutron measurements, is used to characterize source rocks. 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 understand that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: A low value of Th/U ratio as determined from natural gamma radiation is indicative of deepwater sedimentation. This, together with estimates of total organic carbon from pulsed neutron measurements, is used to characterize source rocks. 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 understand that it will not be used to interpret or limit the scope or meaning of the claims.

Abstract: Elemental analysis of an earth formation is obtained using measurements from a gamma ray logging tool. From the elemental analysis, an estimate of the Calcium, Magnesium and Carbon content of the formation is determined. The amount of organic carbon in the formation is estimated from the total Carbon content and the inorganic carbon associated with minerals in the formation. An indication of source rock may be obtained from the Th/U ratio. 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.

Abstract: Methods, systems, apparatus and processes for determining the lithology as well as the mineralogy of subterranean formations surrounding a borehole are described. According to the methods and processes, well log data measurements from neutron spectroscopy applications and associated tool response parameters are solved using an artificial intelligence system, such as an expert system, which in turn generates an appropriate discriminator and/or compositional model that estimates both general and specific lithology as well as the mineralogy constraints of the subterranean formation being analyzed. The methods exhibit good elemental correlation between conventional methods of lithology and mineralogy determination, and can provide numerous output data, including grain density and porosity data within zones of the formation.

Abstract: A method for inhibiting the formation of clathrate hydrates in a fluid having hydrate forming constituents is disclosed. More specifically, the method can be used in treating a petroleum fluid stream such as natural gas conveyed in a pipe to inhibit the formation of a hydrate restriction in the pipe. The hydrate inhibitors used for practicing the method are substantially water soluble polymers formed from a N-substituted acrylamide having two nitrogen substituent groups, R.sub.1 and R.sub.2, where R.sub.1 is a hydrocarbon group having from one to ten carbon atoms and zero to four heteroatoms selected from the group consisting of nitrogen, oxygen, sulfur, and combinations thereof, and R.sub.2 is a hydrogen atom or a hydrocarbon group having from one to ten carbon atoms selected from the group consisting of carbon, nitrogen, oxygen, and sulfur; alternatively, R.sub.1 and R.sub.

Abstract: A method for determining at wellsites the swelling-clay content of shales and shaly sandstones earth formations whereby a sample of the formation is washed with a fluid having a water activity substantially less than that of water, which fluid may contain a soluble cation, and measurements of the sample's dielectric constant are made at a preselected frequency for subsequent comparison to calibration curves, thereby obtaining a measurement of the welling-clay content of the formation. The determinations of the swelling-clay content may be performed at different levels depending on the nature of the samples.

Abstract: A method and system for measuring rock electrical properties using time-domain spectroscopy. The rock to be measured is place in direct contact with the substantially flat face of a sample cell. A voltage pulse is launched into a coaxial line connected to the sample cell. The pulse propagates through the sample cell and reflects from the rock. The incident voltage pulse and reflected voltage signal are analyzed to determine the rock's conductivity as well as the rock's dielectric constant over a broad frequency range.