US3750009A
Expired / Lapsed
US
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Apparatus for processing well logging signals including control means for controlling the signal resolution and the speed of response of the signal indicating means
Abstract In accordance with an illustrative embodiment of the present invention, logging measurements of radially shallow conductivity from an electrode logging tool, radially deep and medium conductivity from an induction logging tool, acoustic travel time from a sonic logging tool, as well as natural gamma-ray and spontaneous potential measurements are processed for recording as a function of borehole depth. More specifically, the shallow conductivity measurement signals are averaged and applied to a hybrid logarithmic circuit which operates to form a logarithm function thereof until the signal amplitude reaches a predetermined level at which time a linear function of the measurement signals is formed. The output signals from the hybrid logarithmic circuit are recorded with three separate degrees of resolution using only two galvanometers by multiplexing two signals on one galvanometer. A speed-up circuit is utilized to prevent the galvanometer retrace from appearing on the recording medium. The induction logging signals are processed by suitable computing circuits to sharpen their resolution and then applied to hybrid logarithmic and skin effect circuits which, in addition to forming the logarithmic and linear functions, provides a skin effect correction. The resulting processed induction logging measurements are recorded with differing degrees of resolution and the radially deep measurement signals are combined with acoustic travel time derived porosity measurements to produce indications of the resistivity of the formation fluids.
Apparatus for processing well logging signals derived from an exploring means in a borehole, comprising: means adapted to receive a well logging signal and apply a given function of saie well logging signal to an indicating means; means responsive to the amplitude of said well logging signal for producing a control signal representative of whether said amplitude exceeds a given threshold level; gain switching means responsive to said control signal for controlling the resolution of said given function signal which is applied to an indicating means; means for producing a relatively high amplitude signal in response to changes in said control signal; and means for combining said high amplitude signal with said given function signal so that the combined signal will have a large change in amplitude level whenever said gain switching means is energized.
Claim 2
Dependent Claim
135 words
Apparatus for processing well logging signals derived from an exploring means in a borehole, comprising: means adapted to receive a well logging signal and apply a given function of saie well logging signal to an indicating means; means responsive to the amplitude of said well logging signal for producing a control signal representative of whether said amplitude exceeds a given threshold level; gain switching means responsive to said control signal for controlling the resolution of said given function signal which is applied to an indicating means; means for producing a relatively high amplitude signal in response to changes in said control signal; and means for combining said high amplitude signal with said given function signal so that the combined signal will have a large change in amplitude level whenever said gain switching means is energized.
Claim 3
Dependent Claim
140 words
Apparatus for processing well logging signals derived from an exploring means in a borehole, comprising: means adapted to receive a well logging signal and apply a given function of said well logging signal to a galvanometric indicating means to produce a record thereof; means responsive to the amplitude of said well logging signal for producing a control signal representative of whether said amplitude exceeds a given threshold level; gain switching means responsive to said control signal for controlling the resolution of said given function signal which is applied to an indicating means; means for producing a relatively high amplitude signal in response to changes in said control signal; and means for combining said high amplitude signal with said given function signal so that the galvanometric indicating means will rapidly deflect from one position to another whenever the resolution is changed.
Claim 4
Dependent Claim
140 words
Apparatus for processing well logging signals derived from an exploring means in a borehole, comprising: means adapted to receive a well logging signal and apply a given function of said well logging signal to a galvanometric indicating means to produce a record thereof; means responsive to the amplitude of said well logging signal for producing a control signal representative of whether said amplitude exceeds a given threshold level; gain switching means responsive to said control signal for controlling the resolution of said given function signal which is applied to an indicating means; means for producing a relatively high amplitude signal in response to changes in said control signal; and means for combining said high amplitude signal with said given function signal so that the galvanometric indicating means will rapidly deflect from one position to another whenever the resolution is changed.
Claim 5
Independent Claim
148 words
A method of processing well logging signals derived from an exploring means in a borehole, comprising: receiving a well logging signal representative of a formation characteristic and applying a given function of said well logging signal to an indicating means; producing at least two signals representative of at least two separate resolutions of said given function signal; producing a control signal representative of whether said amplitude exceeds a given threshold level in response to the amplitude of said well logging signal; selecting one of said at least two separate resolution signals for application to an indicating means in response to said control signal; producing a relatively high amplitude signal in response to changes in said control signal; and combining said high amplitude signal with said selected given function signal so that the combined signal will have a large change in aMplitude level whenever said control signal changes state.
Claim 6
Independent Claim
148 words
A method of processing well logging signals derived from an exploring means in a borehole, comprising: receiving a well logging signal representative of a formation characteristic and applying a given function of said well logging signal to an indicating means; producing at least two signals representative of at least two separate resolutions of said given function signal; producing a control signal representative of whether said amplitude exceeds a given threshold level in response to the amplitude of said well logging signal; selecting one of said at least two separate resolution signals for application to an indicating means in response to said control signal; producing a relatively high amplitude signal in response to changes in said control signal; and combining said high amplitude signal with said selected given function signal so that the combined signal will have a large change in aMplitude level whenever said control signal changes state.