A system and method calibrate efficiency of a gas extraction system in extracting hydrocarbons from mud flowing in a drilling operation. A background reading of a hydrocarbon is extracted from the mud flowing in the drilling operation with the gas extraction system and is checked for stability. An injection operation injects a known concentration of the hydrocarbon into mud, and a subject reading of the hydrocarbon is obtained with the gas extraction system during the injection operation. A correction factor of the hydrocarbon is determined for the gas extraction system by comparing the subject reading against its corresponding known concentration. Then, at least one operational reading of the hydrocarbon extracted from the mud with the gas extraction system can be corrected using the determined correction factor.

A disclosed example embodiment of a fluid extraction system includes a fluid circuit fluidly coupled to a source of a fluid and configured to receive a fluid sample from the source, and a fluid separator arranged in the fluid circuit and configured to receive the fluid sample. The fluid separator includes a body that defines at least one fluid inlet, a flow chamber defined within the body, and is configured to receive and spin the fluid sample from the at least one fluid inlet. The fluid sample spirals inward and forms a vortex, and gases entrained within the fluid sample separate and migrate toward a center of the vortex. An outlet defined in the flow chamber provides a gas outlet that entrains and removes the gases and a liquid outlet receives and removes a remaining portion of the fluid sample.

Systems and methods for extracting hydrocarbon gas utilize a vacuum chamber with a mud chamber portion that is expandable and contractible. Gas is extracted at vacuum pressures.

Disclosed is a method for identification of malfunctioning of a drill bit during drilling of hydrocarbon wells, including: measurement of the rate of penetration of the drill bit, measurement of the drilling length, measurement of the concentration in the drilling mud of at least one gas species belonging to the group of the alkenes, measurement of the torque at the drill bit, analysis of the microscopic structure of the drilling cuttings on the basis of the values assumed by these measurements and on the basis of the observations of this microscopic structure, generation of an alert signal and return of the drill bit to the surface.

Gas-extraction device (152) for extracting at least one gas contained in a drilling mud, the device comprising: —an enclosure (162), —an equipment (164) for supplying the drilling mud to the enclosure (162), —an equipment (170) for introducing a carrier gas into the enclosure (62; 162), wherein the device comprises a flow regulator (204) able to regulate the flow rate of a gas flow containing at least carrier gas, and a pressure controller situated downstream of the enclosure (162) configured for locally setting a pressure lower than the pressure of the enclosure (162), wherein the flow, regulator (204) is interposed between the pressure controller and the enclosure (162).

A system includes an extraction system having an inlet channel and an outlet channel to receive fluid and to output processed fluid. The system also includes an extraction device to capture a first sample of fluid from the inlet channel, capture a second sample from the processed fluid from the outlet channel, and extract gas, liquid, or solids from the first sample and further gas, liquid, or solids from the second sample. Additionally, the system includes a gas, liquid, or solids analyzing device useable to analyze the gas, liquid, or solids to determine a first value of a chemical species of interest present in the first sample and to analyze the further gas, liquid, or solids to determine a second value of the chemical species of interest present in the second sample to determine an efficiency of the extraction system using the first value and the second value.

A process for producing a base oil composition particularly adapted for use in oil-base drilling mud compositions. The process includes contacting drilling waste containing an oil-base mud phase with a solvent to produce a mixture of liquids and solids, separating the two phases, partially evaporating the liquids phase to produce an oil base composition substantially lacking low molecular weight carbon chain compounds and also lacking significant concentrations of benzene, toluene, xylene, and/or ethyl benzene, and having increased closed-cup flashpoint when compared to the oil-base mud phase in the drilling waste. The resulting base oil has enhanced health and safety characteristics for workers interacting with and otherwise exposed to the oil base composition during transporting, conditioning or using such compositions. The base oil produced and drilling methods using the recovered and recycled mud are also described.

A semi-submersible drilling vessel has a deckbox structure and a shaker room. A downward sloping mud return line is provided that passes mud from the diverter to the shaker room. In the shaker room there are one or more shale shaker devices, one or more upstream mud tanks arranged to receive gas cut mud from the one or more shale shaker devices, and a vacuum degasser having an inlet pipe extending into an upstream mud tank, a vacuum tank, a vacuum pump, and an outlet, and a degassed mud tank receiving degassed mud from the outlet of the vacuum degasser. The degassed mud tank has an effective height between the bottom thereof to the operational mud level in said degassed mud tank that is greater than the corresponding effective height of said one or more upstream mud tanks. The degassed mud tank is mounted so that—in operation—the operational mud level in said degassed mud tank is at least 1.5 meter, preferably at least 2 meters, higher than in said one or more upstream tanks with the vacuum degassers self-suction effect causing the mud to be pumped from the upstream tank, via the vacuum degasser, into the degassed mud tank.

Apparatus and methods for degassing and analyzing drilling fluid discharged from a wellbore at an oil and gas wellsite. The apparatus may be a drilling fluid analysis system having a gas analyzer, a fluid analyzer, and a degasser operable to release and separate mud gas entrained in the drilling fluid. The degasser may include a gas-liquid separator having a separator inlet configured to receive the drilling fluid containing the entrained mud gas, a first separator outlet for discharging the mud gas fluidly connected with the gas analyzer, and a second separator outlet for discharging degassed drilling fluid fluidly connected with the fluid analyzer.

A stochastic control method includes determining a property of a solid present in a drilling fluid circulating within a mud circulation system and identifying a mud circulation model that dictates operation of the mud circulation system. The mud circulation model is based on one or more models of one or more uncertainties encountered during a wellbore drilling operation. The method further includes determining an accuracy of the mud circulation model based on a difference between the determined property of the solid present in the drilling fluid and a solid property of the drilling fluid as provided by the mud circulation model, and programming a controller of the mud circulation system based on the mud circulation model to modify operation of the mud circulation system.