An apparatus for performing a well test operation includes a tubular member having a surge chamber and a valve that can control fluid flow from a well into the surge chamber during the well test operation. The apparatus can also include a flow control device, in addition to the valve, for further controlling fluid flow into the surge chamber from the well. Flow rate and pressure data can be measured during the well test operation and used to estimate reservoir properties. Various other systems, devices, and methods are also disclosed.

A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

A central member defines a sample chamber and includes an elastic material configured to enclose at least a portion of a sample, acoustic sensors configured to detect sound waves in the sample chamber, and acoustic emitters configured to emit sounds waves in the central member. A pressure-retaining case is configured to contain a pressurized fluid between an annulus formed between the pressure-retaining case and the central member. A switch is configured to connect or disconnect a pulser and receiver circuit to a specified emitter of the acoustic emitters. A data acquisition unit is configured to receive a signal from each of the acoustic sensors. A pulser and receiver circuit is configured to send an electric pulse to an acoustic emitter and a control signal to the data acquisition unit.

A key seal preferably includes a first circular seal portion, a second rounded seal portion and a third rounded seal portion. The first circular seal portion preferably has generally circular cross-section. The second rounded seal portion preferably has a bottom side which is connected to the first seal portion, and has a cross-section which is smaller than that of the first circular seal portion. The third rounded seal portion preferably has a top side which is connected to the first seal portion, and has a cross-section which is smaller than that of the first circular seal portion. The first, second and third seal portions may be integrally formed. They key seal may be installed in a hydroseal assembly around the pin section of a hydroseal, and between a seal and a block section of the hydroseal.

A downhole sampling tool includes a tool body defining an opening therein for drawing a formation fluid into the downhole sampling tool. At least one sampling vessel is carried in the tool body and is operatively coupled to the opening to receive the formation fluid therein. A closure member is selectively engageable with the opening to prohibit flow of the formation fluid through the opening, and a biasing mechanism is operably coupled to the closure member. The biasing mechanism biases the closure member into engagement with the opening and is responsive to an increase in hydraulic pressure on the exterior of the sampling tool to a predetermined threshold pressure to permit movement of the closure member away from the opening and permit flow of the formation fluid through the opening and into the sampling vessel.

A downhole sampling tool includes a tool body defining an opening therein for drawing a formation fluid into the downhole sampling tool. At least one sampling vessel is carried in the tool body and is operatively coupled to the opening to receive the formation fluid therein. A closure member is selectively engageable with the opening to prohibit flow of the formation fluid through the opening, and a biasing mechanism is operably coupled to the closure member. The biasing mechanism biases the closure member into engagement with the opening and is responsive to an increase in hydraulic pressure on the exterior of the sampling tool to a predetermined threshold pressure to permit movement of the closure member away from the opening and permit flow of the formation fluid through the opening and into the sampling vessel.

A system includes a casing configured to mount within an open hole of a wellsite and a monitoring system configured to mount outside of the casing and monitor a geological formation. The monitoring system includes a perforating device outside of the casing, where the perforating device is configured to produce one or more perforations into the geological formation outside of the casing in a perforating operation of the monitoring system, where the one or more perforations are configured to enable fluid flow between the geological formation and the monitoring system. The system also includes a fluid circuit outside of the casing, where the fluid circuit is coupled to the perforating device, and the fluid circuit is configured to route a first fluid from the geological formation to a sample collecting system during a sampling operation of the monitoring system.