A method of monitoring a subterranean operation includes sampling fluid from a borehole during the operation, and estimating, in near real time, a concentration of one or more gases in the sampled fluid and an isotope composition of the sampled fluid. The method also includes identifying an operational inefficiency in the operation based on the isotope composition associated with the one or more gases, and performing, during the operation, at least one of: alerting an operator and adjusting an operational parameter of the operation, based on identifying the operational inefficiency.

Methods and systems are provided that combine NMR and IR spectroscopy measurements on a rock sample to determine data representing at least one property of the rock sample. In one embodiment, cuttings can be split into first and second lots. Results of an NMR measurement performed on the first lot of cuttings without cleaning can be analyzed to determine pore volume of the cuttings. Results of an IR spectroscopy measurement performed on the second lot of cuttings after solvent cleaning can be analyzed to determine matrix density of the cuttings. Porosity can be determined from the pore volume and matrix density of the cuttings. In another embodiment, combined NMR and IR spectroscopy measurements can be performed on an unprepared rock sample (without solvent cleaning) to characterize properties of kerogen in the rock sample and porosity. In another aspect, a method is provided that employs multi-nucleic NMR measurements to determine porosity.

A drilling system for drilling a borehole. The drilling system includes a drilling fluid pump operable to circulate fluid through the borehole and a fluid analysis system to analyze returned fluid from the borehole. The fluid analysis system includes a sensor system, a recirculation system, and a control system in electronic communication with the drilling fluid pump and the recirculation system. The sensor system is operable to measure one or more properties of the returned fluid. The recirculation system includes a pump and controllable valves and is operable to control flow of the returned fluid through the fluid analysis system.

Systems and methods include a method for generating a real-time reservoir porosity log. Historical gas-porosity data is received from previously-drilled and logged wells. The historical gas-porosity data identifies relationships between gas measurements obtained during drilling and reservoir porosity determined after drilling. A gas-porosity model is trained using machine learning and the historical gas-porosity data. Real-time gas measurements are obtained during drilling of a new well. A real-time reservoir porosity log is generated for the new well using the gas-porosity model and real-time gas measurements.

Various embodiments include apparatus and methods to estimate properties of rock, drill bit, or a combination thereof associated with a drilling operation. The properties can include, but are not limited to, rock chip size, drill bit dullness, drilling efficiency, or a combination selected from rock chip size, drill bit dullness, and drilling efficiency. The estimate may be accomplished from correlating detected acoustic emission with detected electromagnetic emissions. In various embodiments, formation brittleness may be determined. The various estimates may be used to direct a drilling operation. Additional apparatus, systems, and methods are disclosed.

A shale shaker system. The system includes a fluid transport pipe configured to receive a stream of drill cuttings and fluid returns from a wellbore during a drilling operation; an analysis module configured to receive at least a portion of the stream of drill cuttings and fluid returns at an inlet; a cuttings chute configured to receive at least a portion of the stream of drill cuttings and fluid returns from an outlet of the container, and deliver them to a screen box; and one or more screens for filtering drill cuttings from the fluid returns. The analysis module comprises logging sensors configured to operate while drill cuttings are moving through the system. The logging sensors communicate with a processor to determine characteristics of the drill cuttings in real time. A method for analyzing drill cuttings at a well site is also provided.

In one aspect, a system (5) for use in providing an approximation or estimation of a characteristic (for example, a bulk density value) of a deposit subject to a drilling operation is disclosed. In one form, the system (5) comprises a processor module (25) arranged in operable association with a network of sensors (30) operable for measuring one or more parameters relating to the operation of the drilling assembly (10). The processor module (25) is configured operable for receiving data/information derived from the network of sensors (30), and processing the data/information so as to provide a representation of the incursion (eg. depth of penetration into the relevant deposit) achieved by way of the drilling assembly (10). The processor module (25) is further configured for processing the representation of the incursion with a predetermined relationship that is characteristic of, or unique to, the drilling assembly (10) for providing or allowing an approximation/estimation of the characteristic of the deposit as a function of one or more parameters of the incursion to be made.

A method may include measuring a formation sample using a Raman spectrometer to determine a formation sample characteristic, wherein the formation sample characteristic is mineral ID and distribution, carbon ID and distribution, thermal maturity, rock texture, fossil characterization, or combinations thereof.

An automated or robotic mud-logger having a slurry sampler to collect a slurry sample online from a drilling fluid circuit contemporaneous with drilling of a borehole, the slurry sample including drilling fluid and rock cuttings. A liquid separator removes drilling fluid from the slurry sample and discharges a sample of the rock cuttings. A spectrometer performs elemental analysis of the sample of the rock cuttings substantially in real time with collection of the slurry sample.

Systems and methods are disclosed for using downhole plasma discharge effects to determine porosity and/or permeability of formation material. In some embodiments, a method includes determining a concentration of at least one chemical reaction product in a drilling fluid that has interacted with a plasma discharge proximate formation material. A relation between arc and spark of the plasma discharge is determined based, at least in part, on the at least one chemical reaction product, and at least one of porosity and permeability of the formation material is determined based, at least in part, on the relation between arc and spark.