摘要:
A sample preparation apparatus and method of preparing a rock sample using such an apparatus, as useful in connection with the digital numerical simulation of properties of the rock. The disclosed apparatus includes a fixably mounted diamond wire cutter. Three linear translation stages are coupled to a specimen holder. One of the translation stages moves the specimen in a direction parallel to the plane of the cutting wire. The other two translation stages move the specimen in different directions from one another, and when actuated together, advance the specimen into the wire for short distances in a direction out of the plane of the cutting wire. Short piecewise linear cuts are made in the specimen, to provide a sample of the desired shape with a small cross-section.
摘要:
The output spectrum of a controllable swept-frequency acoustic source at a given frequency can be controlled by making the rate of change of frequency equal to the desired output power spectrum divided by the squared envelope amplitude of the source output signal, both measured at the time after the start of its frequency sweep at which the sweep frequency passes through the given frequency. The system and method can also be used to correct for propagation effects outside the source by dividing the desired spectrum by the propagation effect. The method can further be used either to obtain an output spectrum of a desired shape from a source operating at maximum output or to design a sweep of a minimum feasible duration that will result in an output spectrum of a specified shape and with a specified amplitude.
摘要:
A testing system for performing image based direct numerical simulation to characterize petrophysical properties of a rock sample under the simulated deformation condition, for example as representative of subsurface conditions. A digital image volume corresponding to x-ray tomographic images of a rock sample is segmented into its significant elastic phases, such as pore space, clay fraction, grain contacts and mineral type, and overlaid with an unstructured finite element mesh. A simulated deformation is applied to the segmented image volume, and the resulting deformed unstructured mesh is numerically analyzed, for example by way of direct numerical simulation, to determine the desired petrophysical properties.
摘要:
A piston (600) includes a piston housing (601) and a decompression valve (620) disposed in the piston housing. The decompression valve includes a valve housing (630) seated in the piston housing and a valve member (640) moveably received by the valve housing. The valve member (640) has a radially outer surface including an annular shoulder. In addition, the piston includes an end cap (670) secured to the first end of the piston housing. A radially inner surface of the end cap includes an annular valve seat (674). The decompression valve has a closed position with the annular shoulder of the valve member engaging the valve seat of the end cap and an open position with the annular shoulder of the valve member axially spaced from the valve seat of the end cap. The piston also includes a biasing member (660a,660b,660c,660d) configured to bias the decompression valve to the closed position.
摘要:
Multiple sensors on a drill string can be utilized to perform equivalent circulation density (ECD) analysis. By utilizing multiple ones of the sensors, the pressure drop in each section of the wellbore can be classified. Additionally, the inclusion of multiple sensors in the drill string allows a wellbore to be sectioned into intervals bounded by any two sensors. Pressure events occurring in a single section of the wellbore bounded by any two sensors can be isolated and analyzed. The isolation can be achieved by subtracting the pressure measured on the shallower sensor from that measured on the deeper sensor.
摘要:
An automatic batch sequence computer control system is configured to automatically operate process valves in a delayed coker for a complete coke drum cycle. Double verification of the movement of the process valves is used to confirm advancing to the next step. Primary verification is achieved by using position sensors on the valves. Secondary verification is achieved by using monitored process conditions and confirming the measured conditions correlate with expected process conditions for an arrangement of valve positions at a given sequence in the coke drum cycle. A safety interlock system may be integrated with the control system.