Low-frequency strain data recorded with distributed acoustic sensing (das) for hydraulic fracturing monitoring

A computing system, comprising:

• one or more processors;
• and
• a memory system comprising one or more non-transitory computer-readable media storing instructions that, when executed by at least one of the one or more processors, cause the computing system to perform operations, the operations comprising:
• acquiring surface data during a hydraulic fracturing operation that is performed to produce a hydraulic fracture in a subsurface, wherein the surface data is related to a slurry that is pumped into a well in the subsurface, and wherein the surface data includes a pressure of the slurry, a rate of slurry, and/or a concentration of a proppant in the slurry;
• acquiring downhole data during the hydraulic fracturing operation, wherein the downhole data comprises distributed acoustic sensing (DAS) data, and wherein the DAS data includes strain data acquired from a fiber optic cable in a well;
• formulating a model based upon the surface data and the downhole data to predict strain field propagation in the subsurface which contains the hydraulic fracture;
• implementing an inversion method using the model to determine fracture parameters of the hydraulic fracture, wherein the model implements the inversion method by comparing the surface data, the downhole data, and the strain field propagation, and wherein the fracture parameters comprise a height of the hydraulic fracture, a length of the hydraulic fracture, a width of the hydraulic fracture, a longitude of the hydraulic fracture, a latitude of the hydraulic fracture, a twist angle of the hydraulic fracture, and/or a stimulation efficiency;
• and
• estimating an orientation and/or dimensions of the hydraulic fracture based upon the fracture parameters.

A non-transitory computer-readable medium storing instructions that, when executed by one or more processors of a computing system, cause the computing system to perform operations, the operations comprising:

• acquiring surface data during a hydraulic fracturing operation that is performed to produce a hydraulic fracture in a subsurface, wherein the surface data is related to a slurry that is pumped into a well in the subsurface, and wherein the surface data includes a pressure of the slurry, a rate of slurry, and a concentration of a proppant in the slurry;
• acquiring downhole data during the hydraulic fracturing operation, wherein the downhole data comprises distributed acoustic sensing (DAS) data, wherein the DAS data includes strain data acquired from a fiber optic cable, wherein the strain data has a frequency less than 10 hertz, wherein the fiber optic cable is pumped into the well, coupled to a tubing in the well, or cemented behind a casing in the well, and wherein the well is a monitoring well or a treating well;
• formulating a model based upon the surface data and the downhole data to predict strain field propagation in the subsurface which contains the hydraulic fracture, and wherein the hydraulic fracture is part of a network of natural fractures, hydraulically-induced fractures, and/or reactivated fractures;
• implementing an inversion method using the model to determine fracture parameters of the hydraulic fracture, wherein the model implements the inversion method by comparing the surface data, the downhole data, and the strain field propagation, and wherein the fracture parameters comprise a height of the hydraulic fracture, a length of the hydraulic fracture, a width of the hydraulic fracture, a longitude of the hydraulic fracture, a latitude of the hydraulic fracture, a twist angle of the hydraulic fracture, and a stimulation efficiency;
• estimating an orientation and/or dimensions of the hydraulic fracture based upon the fracture parameters, wherein the orientation and/or dimensions are estimated with quantified uncertainty metrics;
• and
• performing an action based upon and/or in response to the orientation and/or dimensions, wherein the action comprises generating and/or transmitting a signal that recommends, instructs, or causes a physical action to occur related to the slurry.