A master data acquisitions system is provided. A trigger emits a sync signal to be sensed by each of a plurality of data acquisition systems. A controller is communicatively coupled with each of the plurality of data acquisition systems. The controller receives data from each of the data acquisition systems. The data for each of the plurality of data acquisition systems include the sensed sync signal. The controller synchronizes the data from each of the plurality of data acquisition systems by aligning the sensed sync signal for each of the plurality of data acquisition systems.

A master data acquisitions system is provided. A trigger emits a sync signal to be sensed by each of a plurality of data acquisition systems. A controller is communicatively coupled with each of the plurality of data acquisition systems. The controller receives data from each of the data acquisition systems. The data for each of the plurality of data acquisition systems include the sensed sync signal. The controller synchronizes the data from each of the plurality of data acquisition systems by aligning the sensed sync signal for each of the plurality of data acquisition systems.

The present disclosure provides a method of processing data obtained from distributed optical fiber sensors to detect acoustic energy generated by a poroelastic effect of fractures in a structure, such as a rock formation. The sensing fiber of an optical fiber distributed sensing system may be deployed in the vicinity of the region where fracturing is occurring, for example, along a well that is offset from a treatment well undergoing hydraulic fracturing. The DAS data obtained from along the sensing fiber is processed to measure changes in the low-frequency strain caused by the poroelastic effects in the rock as the fractures open and close. This measured strain rate data is iteratively processed at each instant time to identify fracture opening features (characterised as compression-tension-compression) that are correlated with fracture closing features (characterised as tension-compression-tension) as a function of depth, to thereby identify and locate fracture hits in the vicinity of the sensing fiber.

A DAS VSP technique is used to determine the induced fracture height and fracture density of an induced fracture region. The DAS VSP technique obtains pre-hydraulic fracturing DAS VSP survey time-lapse data to establish a baseline reference for the direct acoustic wave travel time. The DAS VSP technique obtains one or more time-lapse data corresponding to the subsequent monitor surveys conducted after each hydraulic fracturing stage along the well. Forward modeling is used to determine a theoretical acoustic wave travel time difference. The forward modeling uses seismic anisotropy to describe the behavior of seismic waves traveling through the induced fracture regions. An inversion scheme is then used to invert for the induced fracture height and the fracture density using the forward modeling. The two extracted induced fracture characteristics may then be used to determine optimal hydraulic fracturing parameters.

A method for improving a signal-to-noise ratio of distributed acoustic sensing data may comprise transmitting an acoustic wave from an acoustic source into a subterranean formation, recording a first acoustic noise at a first time interval with a distributed acoustic sensing system, recording at least one acoustic wave and a second acoustic noise at a second time interval with the distributed acoustic sensing system, calculating a noise spectrum from the first time interval, calculating the noise spectrum in the second time interval, and removing the noise spectrum from acoustic data measured during the second time interval to identify acoustic data of the subterranean formation. A system may comprise an acoustic source, a distributed acoustic sensing system disposed within a well, and an information handling system.

Methods and systems for characterizing fractures in a subterranean formation are provided. The method includes introducing an encapsulated explosive unit into a casing located in a wellbore within the subterranean formation and maintaining the encapsulated explosive unit in a stage of the casing. The method also includes detonating the encapsulated explosive unit within the stage to generate a pressure wave that passes through a group of perforations and into the fractures and measuring a reflected pressure wave using a pressure sensor coupled to the bridge plug to produce a pressure measurement. The method further includes converting the pressure measurement into an acoustic signal correlated with the pressure measurement by an acoustic signal generator contained in the bridge plug and transmitting the acoustic signal to apply acoustic pressure on a fiber optic cable coupled to an exterior surface of the casing.

A distributed acoustic system may comprise an interrogator which includes a single photon detector, an umbilical line comprising a first fiber optic cable and a second fiber optic cable attached at one end to the interrogator, and a downhole fiber attached to the umbilical line at the end opposite the interrogator. A method for optimizing a sampling frequency may comprise identifying a length of a fiber optic cable connected to an interrogator, identifying one or more regions on the fiber optic cable in which a backscatter is received, and optimizing a sampling frequency of a distributed acoustic system by identifying a minimum time interval that is between an emission of a light pulse such that at no point in time the backscatter arrives back at the interrogator that corresponds to more than one spatial location along a sensing portion of the fiber optic cable.

A mud pulse telemetry valve and method including a flow tube having at least one upper hydraulic opening extending from an inner surface and at least one lower hydraulic opening extending from an inner surface, a flow restriction member positioned in the flow tube and defining an orifice, an orifice housing connected to the flow tube and supporting the flow restriction member, and a screen defining a flow path from a first end of the screen to the orifice. The orifice housing has at least one inlet port in fluid communication with the upper hydraulic opening upstream of the flow restriction member, and the screen has a plurality of filter openings positioned between the flow path and the at least one inlet port. The mud pulse telemetry valve further has a control valve assembly and a pilot valve assembly.

One or more first sensors may be configured to sense seismic signals and one or more second sensors may be configured to sense electromagnetic crosstalk signals. The second sensors are not responsive to the seismic signals. The data from the first and second sensors may be recorded as first data and second data, respectively. The first data may be modified based on the second data to remove the electromagnetic crosstalk noise form the seismic data.

A hybrid sensing apparatus for collecting data inside a well, the apparatus including an optical cable that acquires a first set of data; and an array of discrete probes connected to each other with an electrical cable. The discrete probes are configured to acquire a second set of data. The apparatus further includes an attachment system attached to the discrete probes and configured to hold the optical cable. The attachment system is configured to expose the optical cable to directly contact the well.