A multi-level cross-district surface well pattern deployment method is provided. Firstly, a horizontal well is drilled from a location on a land surface corresponding to a junction H.sub.1 of a district rise coal pillar of the first district C.sub.1 in a first level and an upper mine field boundary coal pillar. A multilateral well is drilled from a location on the land surface corresponding to a junction H.sub.3 of a level coal pillar between the first and second levels, and the district rise coal pillar of the first district C.sub.1 in the first level. Liquid nitrogen is injected for permeability improvement after a gas drainage quantity decreases to 20% of an initial quantity. Gas drainage is repeated multiple times until the drainage quantity of coal bed methane through a gas drainage pipe of the horizontal pipe is reached 3 m.sup.3/min.

Systems and method for predicting production decline for a target well include generating a static model and a decline model to generate a well production profile. The static model is generated with supervised machine learning using an input data set including historical production data, and calculates an initial resource production rate for the target well. The decline model is generated with a neural network using the input data and dynamic data (e.g., an input time interval and pressure data of the target well), and calculates a plurality of resource production rates for a plurality of time intervals. The system can perform multiple recursive calculations to calculate the plurality of resource production rates, generating the well production profile. For instance, the predicted resource production rate of a first time interval is used as one of inputs for predicting the resource production rate for a second, subsequent time interval.

A method of managing a well system includes: obtaining, based on a predetermined monitoring criterion, well dynamics behavior data of the well system; obtaining modeled well dynamics behavior data for the well system using a physics-based model; decomposing each of the well dynamics behavior data and the modeled well dynamics behavior data into a plurality of frequency band components based on a plurality of predetermined frequency partitions; training a physics constrained machine learning model using one or more machine learning algorithms based on the plurality of frequency band components of the decomposed well dynamics behavior data and the decomposed modeled well dynamics behavior data as input data; obtaining new well dynamics behavior data of the well system; outputting predicted well dynamics behavior data based on the new well dynamics behavior data using the physics-based model and the trained physics constrained machine learning model.

A method of managing a well system includes: obtaining, by a digital twin manager and based on a predetermined monitoring criterion, well mass flow data of the well system; obtaining, by the digital twin manager, modeled well mass flow data for the well system using a physics-based model; training, by the digital twin manager, a physics constrained machine learning model using one or more machine learning algorithms based on the well mass flow data and the modeled well mass flow data as inputs; obtaining, by the digital twin manager, real-time well mass flow data of the well system; outputting, by the digital twin manager, predicted well mass flow data using the real-time well mass flow data and the trained physics constrained machine learning model; and transmitting, by the digital twin manager, a command to the well system that adjusts a well operation based on the predicted well mass flow data.

A perforating gun with one or more centralizing charge tube inserts and, optionally, an orienting centralizer, used in oil and gas completions operations. A gun string including the perforating gun and one or more additional perforating guns substantially identical to the perforating gun.

A perforating gun with one or more centralizing charge tube inserts and, optionally, an orienting centralizer, used in oil and gas completions operations. A gun string including the perforating gun and one or more additional perforating guns substantially identical to the perforating gun.

A method of managing a well system includes: obtaining, by a digital twin manager and based on a predetermined monitoring criterion, well dynamics behavior data of the well system; obtaining, by the digital twin manager, modeled well dynamics behavior data for the well system using a physics-based model; training, by the digital twin manager, a physics constrained machine learning model using one or more machine learning algorithms based on the well dynamics behavior data and the modeled well dynamics behavior data as input data; obtaining, by the digital twin manager, real-time well dynamics behavior data of the well system; outputting, by the digital twin manager, predicted well dynamics behavior data using the real-time well dynamics behavior data, the physics-based model, and the trained physics constrained machine learning model; and transmitting a command to the well system that adjusts a well operation based on the predicted well dynamics behavior data.

Implementations described and claimed herein provide systems and methods for a framework to achieve completion optimization for waterflood field reservoirs. The proposed methodology leverages adequate data collection, preprocessing, subject matter expert knowledge-based feature engineering for geological, reservoir and completion inputs, and state-of-the-art machine-learning technologies, to indicate important production drivers, provide sensitivity analysis to quantify the impacts of the completion features, and ultimately achieve completion optimization. In this analytical framework, model-less feature ranking based on mutual information concept and model-dependent sensitivity analyses, in which a variety of machine-learning models are trained and validated, provides comprehensive multi-variant analyses that empower subject-matter experts to make a smarter decision in a timely manner.

A clamp connection for use with flowlines of a hydraulic fracturing operation has a female clamp hub having a seal pocket formed in the face thereof, a male clamp hub having a raised face at an end thereof, an elastomeric seal received in the seal pocket of the female clamp hub, and a clamp connector extending around the female clamp hub and the male clamp hub so as to maintain the male clamp hub and the female clamp hub in a liquid-tight relationship. The male clamp hub has an annular protrusion extending outwardly of the raised face. The annular protrusion bears against a side of the elastomeric seal. The raised face of the male clamp hub is received in an interior of the female clamp hub.

An apparatus for generating acoustic waves in a medium to stimulate oil recovery within an oil reservoir, the apparatus being operable with a single moving part—a central rotor. The apparatus being suitable for use in association with a system to facilitate the co-generation of geothermal energy or sequestration and storage of CO.sub.2.