Abstract: A wellbore tool has an electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid downhole in a wellbore. The sensor comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane the other side of the membrane being exposed to a chamber containing at least two electrodes and containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid. Measurement is made by passing formation fluid along the flow path and repeatedly applying varying potential to one electrode and measuring the peak current flowing between that electrode and a second electrode.

Abstract: A wellbore tool has an electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid downhole in a wellbore. The sensor comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane the other side of the membrane being exposed to a chamber containing at least two electrodes and containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid. Measurement is made by passing formation fluid along the flow path and repeatedly applying varying potential to one electrode and measuring the peak current flowing between that electrode and a second electrode.

Abstract: An electrochemical sensor for measuring the amount of hydrogen sulphide or thiols in a fluid in a wellbore comprises a temperature- and pressure-resistant housing containing a flow path for the fluids. The fluids flow over one side of a gas permeable membrane made of zeolite or a suitable ceramic material, the other side of the membrane being exposed to a chamber containing a reaction solution which together with the hydrogen sulphide or thiols create a redox reaction resulting in an electrical current dependent upon the amount of hydrogen sulphide or thiols in the fluid.

Abstract: A receptacle (10) for use in collecting samples down a well bore (14) is provided, the receptacle comprising a plurality of interconnecting modules (22, 24, 26, 30, 32, 34). A main chamber (22) is capable of holding a sample, and sensors (58, 60, 62, 64) within the chamber detect physical and chemical characteristics of the sample. Valves (50, 52) in a chamber wall seal the chamber (22) after a fluid sample has been collected. A communication means is placed in communication with the chamber (22) so as to provide an externally accessible port which communicates with the inside of the chamber (22) and allows detection and analysis of sample characteristics without removing the sample from the sealed chamber (22). The chamber (22) includes a piston (82) which is adjustable to keep pressure constant in the chamber and a heating element (58) to keep temperature constant. A method for sampling downhole fluids is also provided.

Abstract: A receptacle (10) for use in collecting samples down a well bore (14) is provided, the receptacle comprising a plurality of interconnecting modules (22, 24, 26, 30, 32, 34). A main chamber (22) is capable of holding a sample, and sensors (58, 60, 62, 64) within the chamber detect physical and chemical characteristics of the sample. Valves (50, 52) in a chamber wall seal the chamber (22) after a fluid sample has been collected. A communication means is placed in communication with the chamber (22) so as to provide an externally accessible port which communicates with the inside of the chamber (22) and allows detection and analysis of sample characteristics without removing the sample from the sealed chamber (22). The chamber (22) includes a piston (82) which is adjustable to keep pressure constant in the chamber and a heating element (58) to keep temperature constant. A method for sampling downhole fluids is also provided.

Abstract: A well fluid sampling tool and method for retrieving reservoir fluid samples from deep wells. The sampling tool is lowered to the required depth, an internal sample chamber is opened to admit well fluid at a controlled rate, and the sample chamber is then automatically sealed. The temperature of the sampled well fluid is maintained at or near initial as-sampled temperature to avoid the volumetric shrinkage otherwise induced by temperature reduction, mitigate precipitation of compounds from the sample, and/or maintain the initial single-phase condition of the sample. The sample chamber is thermally insulated, provided with a storage heater, electrically heated, given a high hear capacity, and/or pre-heated to sample temperature.