Abstract: A method for determining change in stress in a reservoir formation includes inducing a pressure pulse in a first well hydraulically connected by a fracture to the reservoir formation. A stress-related attribute of the fracture is determined from reflection events detected in pressure measurement made in the first well as a result of the inducing the pressure pulse. The inducing and determining are repeated to estimate changes in the stress-related attribute with respect to time. A method for determining and localizing type of interaction between a treated well and an observation well by monitoring pressure and fracture changes in the observation well.

Abstract: A method for determining change in stress in a reservoir formation includes inducing a pressure pulse in a first well hydraulically connected by a fracture to the reservoir formation. A stress-related attribute of the fracture is determined from reflection events detected in pressure measurement made in the first well as a result of the inducing the pressure pulse. The inducing and determining are repeated to estimate changes in the stress-related attribute with respect to time. A method for determining and localizing type of interaction between a treated well and an observation well by monitoring pressure and fracture changes in the observation well.

Abstract: A method for optimizing hydraulic fracturing includes characterizing a fracture induced by pumping fracturing fluid into a subsurface formation. The characterizing includes analyzing properties of reflected tube waves detected in a well. Change in expected characterization of the subsurface formation is modeled with respect to a modeled change in at least one parameter of the pumping fracturing fluid. The modeled change is compared to a measured change in the characterization with respect to an actual change in the at least one parameter. The modeled change and the measured change are used to train a machine learning algorithm to determine an optimized change in the at least one parameter.

Abstract: Method for monitoring at least one point system of a railway network comprising the steps of placing several sensors in correspondence of said at least one point system; acquiring from said sensors current and voltage signals of a point machine during a maneuver; and segmenting the signals of the maneuver according to different predetermined phases of movement. Then extracting predetermined features from each segment; comparing the extracted features with a set of predetermined values which represent a “healthy” maneuver, thus obtaining a global indicator representative of the conditions of the maneuver at the point system; and comparing said global indicator with a failure threshold, and if it exceeds said failure threshold, detecting a failure in the point system.