Abstract: A method and ultrasonic meter system for determining pipe roughness. At least some of the illustrative embodiments are ultrasonic meters comprising a spool piece that couples within a flow of fluids, and a first transducer pair mechanically mounted to the spool piece and acoustically coupled to the flow of fluids (wherein the first transducer pair comprises an upstream transducer and a downstream transducer in operational relationship to the upstream transducer and defines a first chord there between). The ultrasonic meter is configured to determine diagnostic data based on acoustic signals transmitted between the first transducer pair (wherein the diagnostic data comprises an asymmetry of the flow of fluids in the spool piece, a cross flow of the flow of fluids in the spool piece, and a profile factor of the flow of fluids in the spool piece).

Abstract: Methods and related systems for determining transducer delay time and transducer separation in ultrasonic flow meters. At least some of the illustrative embodiments are a method comprising measuring a delay time for a first transducer pair, measuring a total measured time for ultrasonic signals transmitted between a second transducer pair in an ultrasonic meter in which both the first and second transducer pairs are installed, calculating a parameter associated with the second transducer pair using the delay time of the first transducer pair and the total measured time for said second transducer pair.

Abstract: A method and related ultrasonic meter identify and correct for transit time errors such as peak switch errors. The method includes calculating values for a set of diagnostics from measurements of the fluid flow, including transit time measurements. Based on the values for the diagnostics, and whether and how they fall outside of their respective ranges, the meter can identify a variety of problems with the meter or fluid flow, such as whether there has been an intermittent peak switch, a permanent peak switch, or the presence of noise, velocity pulsation in the fluid flow, temperature stratification, of other problem. In the event there is a problem with the meter, the meter self-tunes in order to minimize the chances of the problem happening again.

Abstract: An apparatus and related method for measuring the degree of stratified flow in a two-phase flow is disclosed. Alternate embodiments include a single transducer level detector and a multiple transducer level detector. Further, these level detectors may be either integrated into or used in conjunction with an ultrasonic flow meter, or may be used in conjunction with some other meter that determines speed of sound for the flowing gas.

Abstract: An apparatus and related method for measuring the properties and individual flow rates of a two-phase flow comprising a gas and a liquid is disclosed. This apparatus and related method also can determine whether the liquid is travelling in primarily a mist or stratified flow. More precisely, one embodiment of the disclosed invention uses measured parameters such as gain, standard deviation in upstream and downstream travel times for an ultrasonic signal, measured speed of sound, noise, signal quality, batch failure rate, and velocity profile to infer the amount of liquid in the gas flow, and in what form the liquid is travelling. For a horizontal two-phase flow, an internal measurement can be used as a dry gas reference, although the invention is also applicable to a vertical flow. For increased confidence, these determinations may be corroborated by the disclosed liquid level measurement device.

Abstract: Improved methods and systems are provided for determining a volumetric flow rate of mud in a return line without the aid of a velocity probe. A mud level sensor is located in a return line chimney preferably in close proximity to the bell nipple. The sensor senses the height of the mud flowing in the return line. Where an ultraonsic transceiver is used as the sensor, temperature sensors in the chimney and return line determine a temperature gradient in the return line which provides a speed of sound correction as does a target at a known distance from the transceiver. A computer receives the uncorrected mud height and the speed of sound information, and determines the flow-out volume of the mud. Flow-out volume is related to the mud height, the geometry of the return line, and mud parameters. In a more complete system, the computer calibrates the determined flow-out volume with the flow-in volume, and provides a correction factor which is used to provide a corrected flow-out determination.

Abstract: An improved method and apparatus is disclosed for use in a return line system of a drilling rig to determine a volumetric fluid flow rate and, therefore, to aid in detecting a kick in a well. The apparatus comprises an ultrasonic level sensor, an ultrasonic Doppler velocity sensor and a digital computer electrically coupled to the level sensor and the Doppler velocity sensor to determine the fluid flow regime in the return line system. The flow regime is determined by the programmed computer to accurately determine the volumetric fluid flow rate in the return line system in real time, during drilling operations.

Abstract: A device for detecting an interface between two fluids of differing electrical properties, said device having an electrical circuit comprising transmitting means for transmitting electrical impulses to said fluids, a detector of electrical impulses, and at least one probe which is adapted to extend into said fluids; said probe comprising an electrically conductive probe member and a grounded electrically conductive shield, the probe member being mounted within the shield and being spaced from the latter by an air core, the probe member adjacent its distal end portion, being sealed to the shield by a dielectric seal which prevents the ingress of said fluid into the space between the shield and the probe member.

Abstract: A method of determining the mass flow of a fluid comprising measuring a plurality of parameters comprising the pressure P, the temperature T and the density .rho. of the fluid, determining the specific gravity G of the fluid from the said parameters, and using the measured density .rho. together with a further parameter which varies with the volumetric flow to evaluate the mass flow of the fluid only if the so-determined value of G is within a given range of values.

Abstract: A method of testing a fluid is disclosed which comprises passing a main flow of a fluid through a conduit; inserting into said conduit a probe having an inlet opening which faces downstream of the conduit, or is disposed in a chamber communicating with the conduit, the inlet opening communicating with an outlet opening which is disposed in an end surface of the probe; the said main flow, in passing through the conduit, causing a sampling flow of the fluid to be drawn from the conduit, and to be passed through the probe from the inlet opening to the outlet opening, and so back to the conduit; and testing said sampling flow.

Abstract: Surging of a centrifugal compressor is avoided by ensuring that in operation ##EQU1## WHERE K and k are parameters whose values depend on the characteristics of the compressor, g is the acceleration due to gravity, h.sub.p is the polytropic head produced by the compressor, Vc is the velocity of sound in said inlet gas, and Mn (the Mach Number) is the ratio of the flow velocity V of the gas at the inlet to the compressor to the velocity of sound Vc therein. This is normally effected by arranging that ##EQU2## where .DELTA..sub.p is the differential pressure across a throttling member disposed in an inlet duct of the compressor, P.sub.1 is the compressor inlet pressure, and P.sub.2 is the compressor outlet pressure.