摘要:
Various technologies for removing shoulder-bed effects from measurements of an earth formation made in a wellbore. In one implementation, a methodology for removing the shoulder-bed effects includes receiving the measurements and constructing a layered model of the earth formation. Each layer has a set of parameters corresponding to one or more types of the received measurements ascribed to each layer such that the set of parameters define a parameter space for the layered model. The methodology may further include dividing the parameter space into subspaces based on relationships among the parameters, selecting from the subspaces one or more starting points, minimizing a cost function using the one or more starting points to generate one or more candidate solutions having the shoulder-bed effects removed and selecting a final solution from the one or more candidate solutions.
摘要:
A method for displaying a formation model while drilling a wellbore in the formation includes operating a well logging instrument at a measurement point in the formation along a wellbore while the wellbore is being drilled. Measurement data regarding the formation are obtained from the well logging instrument. An actual orientation of a geological structure is determined from the measurement data. A trajectory of the wellbore is displayed in three dimensions as it is being drilled through the formation. While drilling the wellbore, the geological structure is displayed along the trajectory of the wellbore according to the determined actual orientation of the geological structure. The actual orientation reflects an azimuth angle of planes corresponding to the geological structure. The trajectory of the wellbore is changed in response to displaying the determined actual orientation of the geological structure relative to the trajectory.
摘要:
A method for displaying a formation model includes displaying a trajectory representing a three-dimensional structure of the wellbore; and displaying objects representing a bed boundary along the trajectory, wherein the objects are displayed at distances from the trajectory according to measurement data, wherein the objects are displayed in orientations reflecting azimuth angles of planes corresponding to the bed boundary.
摘要:
A method for displaying a formation model while drilling a wellbore in the formation includes operating a well logging instrument at a measurement point in the formation along a wellbore while the wellbore is being drilled. Measurement data regarding the formation are obtained from the well logging instrument. An actual orientation of a geological structure is determined from the measurement data. A trajectory of the wellbore is displayed in three dimensions as it is being drilled through the formation. While drilling the wellbore, the geological structure is displayed along the trajectory of the wellbore according to the determined actual orientation of the geological structure. The actual orientation reflects an azimuth angle of planes corresponding to the geological structure. The trajectory of the wellbore is changed in response to displaying the determined actual orientation of the geological structure relative to the trajectory.
摘要:
A method for identifying environmental effects in well log data includes selecting a plurality of models, each of the plurality of models including at least one parameter to be optimized; fitting the models to the well log data by optimizing the at least one parameter, the fitting producing a plurality of optimized models; determining an indicator of goodness of fit for each of the plurality of optimized models; and selecting a model representing a best fit of the well log data based on the indicator.
摘要:
A downhole tool for formation logging includes a tool body configured to move in a borehole; and at least one sensor module mounted in at least one mounting location on the tool body, wherein the at least one sensor module is interchangeable with other sensor modules that make different measurements. A downhole tool may further comprise a measurement system disposed in the tool body, wherein the measurement system is operatively coupled to the at least one sensor module.
摘要:
A method and apparatus for determining the geometrical characteristics of a well, including insertion of a sonde of elongate shape into the well, the sonde including azimuth electrodes (A.sub.azi), an annular current electrode (A.sub.0), and at least one annular current return electrode (A). The annular current electrode (A.sub.0) emits a current I.sub.0, which flows essentially in a column of mud situated inside the well and returns to the annular current return electrodes. Signals are induced in response to the current I.sub.0 from which can be determined the geometrical characteristics of the well. Alternative embodiments include an apparatus which is symmetrical about the azimuth electrodes. High resolution measurements are obtained by computed focusing. In a first effective operating mode, currents i.sub.1 and i'.sub.1 are emitted from guard electrodes A.sub.1 and A'.sub.1 located on either side of the current electrode (A.sub.0,A'.sub.0), the current I.sub.0,1 emitted by the annular current electrode being equal to 0. In a second effective operating mode, a current I.sub.0,2 is emitted from the current electrode (A.sub.0,A'.sub.0) towards the guard electrodes, the total current I.sub.t,2 emitted from the sonde into the formation being equal to 0. Computed focusing is performed on the basis of the above two effective operating modes to simulate an operating mode in which (i) a current I.sub.0.c is emitted into the surrounding formation from the current electrode (A.sub.0,A'.sub.0); and (ii) the current I.sub.0,c is focused in the formation by emitting two currents I.sub.1,c and I'.sub.1,c from respectively the guard electrodes (A.sub.1,A'.sub.1).
摘要:
A method for reducing stand-off effects of a downhole tool includes disposing the downhole tool in a borehole, wherein the downhole tool comprises at least one moveable section disposed between an energy source and a receiver on the downhole tool; and activating the at least one moveable section to reduce a thickness of at least one selected from a mud layer and a mudcake between the downhole tool and a wall of the borehole. A downhole tool includes an energy source and a receiver disposed on the downhole tool; at least one moveable section disposed between the energy source and the receiver; and an activation mechanism for reducing a thickness of at least one selected from a mud layer and a mudcake between the downhole tool and a wall of a borehole.
摘要:
A well logging tool and method are disclosed comprising a conductive mandrel, an antenna array disposed around the conductive mandrel, wherein the antenna array comprises a plurality of antennas disposed on insulating supports and at least one contact spacer, the at least one contact spacer having at least one conductor channel having a contact assembly disposed therein, a sleeve disposed over the antenna array, wherein the sleeve includes at least one electrode assembly, the at least one electrode and the contact assembly adapted to provide a radially conductive path from an exterior of the well logging tool to the conductive mandrel and wherein the electrode assembly comprises a first conductor exposed to the exterior of the well logging tool and at least one second conductor conductively connected to the first conductor and exposed to an inner surface of the sleeve, wherein at least one of the first conductor or the second conductor being in sealed contact with the sleeve to prevent the passage of fluid through the sleeve.
摘要:
A method of measuring the resistivity of drilling mud in a borehole passing through a terrestrial formation includes the steps of a) inserting a sonde into the borehole, the sonde having an elongate body provided with at least one annular current electrode (A0, A′0) and at least two annular guard electrodes (A, A′, A1, A′1, A2, A′2) situated on either side of the annular current electrode; b) performing computed focusing to simulate an operating mode in which at least one current I0 is emitted into the surrounding formation from the annular current electrode, the current I0 being focused in the formation by emitting two currents I1 and I′1 from the two annular guard electrodes situated on either side of the annular current electrode; and c) producing a signal representative of the resistivity Rm of the drilling mud from the simulated operating mode. Apparatus for measuring the resistivity of drilling mud in a borehole includes the sonde, and electronic circuitry for performing computed focusing and computing a signal representative of the resistivity Rm of the drilling mud on the basis of the computed focusing.