Abstract: Systems and methods include an importance that each of the attributes and features of the well data has on machine learning models. Well data is collected for each well in an unconventional field, including attributes and features of basin data, completion data, and production data. Spatial features are generated for each well in different regions. A combined well features dataset is generated. The dataset maps the well data to the spatial features for each well in the different regions. A training dataset and a testing dataset are generated by splitting the combined dataset. A machine learning model is trained using cross-validation and tuning on the training dataset to predict estimated ultimate recovery (EUR). The performance of a machine learning (EUR) model is evaluated with respect to different regression metrics. An importance that each of the attributes and features of the well data has on machine learning models is determined.

Abstract: A tubing hanger includes a hanger connection profile positioned along a borehole of the tubing hanger and a first landing profile positioned along the borehole and above the hanger connection profile. The first landing profile includes first threads including a first thread feature configured to secure a first check valve to the tubing hanger for isolating a production tubing. The tubing hanger further includes a second landing profile positioned along the borehole and above the first landing profile, the second landing profile including second threads including a second thread feature. The second thread feature is larger than the first thread feature and is configured to secure a second check valve to the tubing hanger for further isolating the production tubing.

Abstract: A wellbore chemical injection assembly includes an extension flange including two ends and defining a flange bore. The first end can be fluidically coupled to a tubing spool inlet of a wellhead installed at a wellbore surface. The second end can be fluidically coupled to a chemical reservoir from which chemical is injected through the flange bore into the tubing spool. The assembly includes a mandrel positioned within the extension flange. A portion of the mandrel resides within the flange bore, while a remainder extends out. The mandrel defines an interior opening spanning an axial length of the mandrel. Outer coupling threads formed on the mandrel can removably mate with counterpart threads in the tubing spool inlet. Inner coupling threads formed on an inner surface of a portion of the interior opening can removably mate with coupling threads on a valve assembly removably seated in the interior opening.

Abstract: A wellbore tieback system that includes a liner, a tieback string, and a seal system. The liner is disposed within a wellbore and defines an annulus between an external surface of the liner and a wall of the wellbore. The tieback string has a receptacle end that defines an inner diameter larger than an outer diameter of the liner such that the receptacle end can be disposed within the annulus to receive a portion of the liner. The seal system is coupled to an internal surface of the receptacle end. The seal system has at last one annular seal that swells inwardly to form, with the portion of the liner inserted within the receptacle end, a seal with the external surface of the liner. The tieback string is fluidly coupled, with the seal formed, to the liner to receive production fluid from the liner.