Method and apparatus for the continuous analysis of drilling mud
First Claim
1. In the logging of a well during drilling thereof, the method of producing a logging signal which represents, on a continuous basis, the instantaneous concentration of a given gaseous component in drilling mud as it is being returned from the well, said method comprising the steps of:
- continuously subjecting at least a portion of said drilling mud being returned from the well to gas separation to separate gas containing said gaseous component from said portion of the returned mud;
continuously and simultaneously subjecting the separated gas to analysis to produce a gaseous component concentration signal whose value at any instant corresponds to the concentration, at that instant, of said given gaseous component in the separated gas;
producing a continuous mud flow rate signal whose value at each instant corresponds to the rate of flow of drilling mud from which the gas is separated;
producing a continuous gas flow rate signal whose value at each instant corresponds to the rate of flow of gas separated from said drilling mud; and
continuously processing said gaseous component concentration signal, said mud flow rate signal and said gas flow rate signal to provide a continuous logging signal whose value at any instant corresponds to the product of the concentration at that instant of the given gaseous component and the rate of flow at that instant of gas separated from said drilling mud divided by the rate of flow at that instant of the drilling mud.
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Accused Products
Abstract
An oil well drilling rig (10) recirculates drilling mud which is analyzed continuously by pumping it through a gas separation unit (72) where the gases in the mud become separated and mixed with a carrier gas and are conveyed to gas analyzing devices (196) where the concentration of the different hydrocarbon components of the gases in the mud are continuously measured and the signals representative of these measurements are processed together with mud flow rate, and the carrier gas flow rate or the sample gas flow rate signals in a signal processor (64) to provide a continuous log of gas component concentration during drilling.
180 Citations
56 Claims
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1. In the logging of a well during drilling thereof, the method of producing a logging signal which represents, on a continuous basis, the instantaneous concentration of a given gaseous component in drilling mud as it is being returned from the well, said method comprising the steps of:
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continuously subjecting at least a portion of said drilling mud being returned from the well to gas separation to separate gas containing said gaseous component from said portion of the returned mud; continuously and simultaneously subjecting the separated gas to analysis to produce a gaseous component concentration signal whose value at any instant corresponds to the concentration, at that instant, of said given gaseous component in the separated gas; producing a continuous mud flow rate signal whose value at each instant corresponds to the rate of flow of drilling mud from which the gas is separated; producing a continuous gas flow rate signal whose value at each instant corresponds to the rate of flow of gas separated from said drilling mud; and continuously processing said gaseous component concentration signal, said mud flow rate signal and said gas flow rate signal to provide a continuous logging signal whose value at any instant corresponds to the product of the concentration at that instant of the given gaseous component and the rate of flow at that instant of gas separated from said drilling mud divided by the rate of flow at that instant of the drilling mud. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. Apparatus for producing a logging signal which represents, on a continuous basis, the instantaneous concentration of a given gaseous component in drilling mud as it is being returned from a well during the drilling thereof, said apparatus comprising:
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means for continuously subjecting at least a portion of drilling mud being returned from a well being drilled to gas separation to separate gas containing said gaseous component from said portion of the returned mud; means for continuously and simultaneously subjecting the separated gas to analysis to produce a gaseous component concentration signal whose value at each instant corresponds to the concentration, at that instant, of said give gaseous component in the separated gas; means producing a continuous mud flow signal whose value at each instant corresponds to the rate of flow of drilling mud from which the gas is separated; means for producing a continuous gas flow rate signal whose value at each instant corresponds to the rate of flow of gas separated from said drilling mud; and means for continuously processing said gaseous component concentration signal, said mud flow rate signal and said gas flow rate signal to provide a continuous logging signal whose value at each instant corresponds to the product of the concentration at that instant of the given gaseous component and the rate of flow at that instant of gas separated from said drilling mud divided by the rate of flow at that instant of the drilling mud. - View Dependent Claims (11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21)
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22. A method of ascertaining the concentration of at least one component of the mud gas in drilling mud during a well drilling operation, said method comprising the steps of:
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continuously passing said drilling mud through an agitating type gas separation device; simultaneously flowing a carrier gas through the mud gas separation device at a rate such that the volume of carrier gas is at least several times greater than the volume of mud gas in the drilling mud; thoroughly mixing the carrier gas in said mud gas separation device with all of the mud therein as well as with the mud gas contained in the mud; separating from said mud gas separation device a gas mixture comprising said carrier gas and said mud gas; subjecting said gas mixture to measurement to produce a component gas signal whose value corresponds to the concentration of said component in said gas mixture; measuring the volume of said carrier gas which flows into said mud gas separation device to produce a carrier gas signal whose value corresponds to said volume of said carrier gas; measuring the quantity of the mud which passes through said mud gas separation device to produce a mud quantity signal whose value corresponds to said quantity of mud; and combining said component gas, carrier gas and mud quantity signals such that the product of the values of the component gas and carries gas signals is divided by the value of the mud quantity signal to produce a concentration signal whose value substantially corresponds to the concentration of said component gas in said drilling mud. - View Dependent Claims (23, 24, 25, 26, 27, 28, 29, 30)
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31. Apparatus for producing a signal representative of the concentration of at least one component of the mud gas in drilling mud during a well drilling operation, said apparatus comprising:
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an agitating type mud gas separation device; means for passing drilling mud, from a well being drilled, through the mud gas separation device; means for simultaneously flowing a carrier gas through the mud gas separation device at a rate such that the volume of carrier gas is at least several times greater than the volume of mud gas in the drilling mud, said agitating type mud gas separation device being operative to thoroughly mix the carrier gas with all of the mud therein as well as with the mud gas contained in the mud; means for separating from said mud gas separation device a gas mixture comprising said carrier gas and said mud gas; means for measuring the concentration of at least one component of the mud gas in the mixture and producing a component gas signal whose value corresponds to the concentration of said component in said mixture; means for measuring the volume of said carrier gas which flows into said mud gas separation device and producing a carrier gas signal whose value corresponds to said volume of said gas; means for measuring the quantity of the mud which passes through said mud gas separation device and producing a mud quantity signal whose value corresponds to said quantity of mud; and means for combining said component gas, carrier gas, and mud quantity signals such that the product of the values of the component gas and carrier gas signals is divided by the value of the mud quantity signals and for producing a concentration signal whose value substantially corresponds to the concentration of said component in said drilling mud. - View Dependent Claims (32, 33, 34, 35, 36, 37, 38)
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39. A mud gas test system for testing the gases contained in drilling mud returned from a well being drilled, said system comprising:
- a gas analyzing device for analyzing gases separated from the drilling mud, a mud gas separation device having a mud inlet, a mud outlet, a carrier gas inlet and a gas mixture outlet, said mud gas separation device being of the type in which carrier gas is mixed with mud passing therethrough to produce a gas mixture with gas contained in the mud, first and second manifolds, means arranged to supply a carrier gas to said first manifold, means, including a first valve, connecting the carrier gas inlet of said mud gas separation device to said first manifold, means, including a second valve, connecting the gas mixture outlet of said mud gas separation device to said second manifold, means including a third valve interconnecting said first and second manifolds and means interconnecting said second manifold and said gas analyzing device.
- View Dependent Claims (40, 41, 42, 43, 44, 45, 46)
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47. A method for determining whether hydrocarbons are present in earth formations as a borehole is drilled therethrough by earth-boring apparatus operatively supported by a string of drill pipe in said borehole for progressively excavating said borehole as a drilling mud is circulated downwardly through said drill string and returned to the surface through said borehole and including the steps of:
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continuously intermixing an inert gas with at least a portion of said drilling mud returning to the surface while said earth-boring apparatus is progressively excavating said borehole for obtaining a mixed stream of said inert gas and at least a measurable portion of formation hydrocarbons that are entrained in successive portions of said returning drilling mud; analyzing said mixed stream of gases for obtaining a first measurement representative of the concentration of at least one formation hydrocarbon in successive portions of said mixed stream; analyzing said inert gas for obtaining a second measurement representative of the concentration of at least said one formation hydrocarbon in said inert gas; correllating said first and second measurements for providing an output signal representative of the concentration of said formation hydrocarbon entrained in said returning drilling mud; and plotting said output signals as a function of borehole depth for determining which of said subsurface formations may contain said formation hydrocarbon. - View Dependent Claims (48, 49, 50, 51)
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52. A method for determining whether hydrocarbons are present in earth formations as a borehole is drilled therethrough by earth-boring apparatus operatively supported by a string of drill pipe in said borehole for progressively excavating said borehole as a drilling mud is circulated downwardly through said drill string and returned to the surface through said borehole and including carrying formation cuttings and entrained formation fluids and including the steps of:
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continuously intermixing an inert gas with at least a portion of said drilling mud returning to the surface while said earth-boring apparatus is progressively excavating said borehole for obtaining a first mixed stream of said inert gas and at least a measurable portion of formation fluids that are entrained in successive portions of said returning drilling mud; analyzing said first mixed streams of gases for obtaining a first measurement representative of the concentration of at least one formation fluid in successive portions of said first mixed stream; intermixing said inert gas with at least a portion of said cuttings returning to the surface for obtaining a second mixed stream of said inert gas and at least a measurable portion of formation fluids that may be entrained in successive portions of said formation cuttings; analyzing said second mixed stream of gases for obtaining a second measurement representative of the concentration of at least one formation fluid entrained in successive portions of said formation cuttings; analyzing said inert gas for obtaining a third measurement representative of the concentration of at least said formation fluid in said inert gas; correllating said measurements for providing a series of output signals representative of the concentration of said formation fluid entrained in said returning drilling mud and said cuttings; and plotting said output signals as a function of borehole depth for determining which of said subsurface formations may contain said formation fluid. - View Dependent Claims (53, 54, 55, 56)
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Specification