Interference fracturing: Nonuniform distributions of perforation clusters that promote simultaneous growth of multiple hydraulic fractures

One of the important hurdles in horizontal-well stimulation is the generation of hydraulic fractures (HFs) from all perforation clusters within a given stage, despite the challenges posed by stress shadowing and reservoir variability. In this paper, we use a newly developed, fully coupled, parallel-planar 3D HF model to investigate the potential to minimize the negative impact of stress shadowing and thereby to promote more-uniform fracture growth across an array of HFs by adjusting the location of the perforation clusters. In this model, the HFs are assumed to evolve in an array of parallel planes with full 3D stress coupling while the constant fluid influx into the wellbore is dynamically partitioned to each fracture so that the wellbore pressure is the same throughout the array. The model confirms the phenomenon of inner-fracture suppression because of stress shadowing when the perforation clusters are uniformly distributed. Indeed, the localization of the fracture growth to the outer fractures is so dominant that the total fractured area generated by uniform arrays is largely independent of the number of perforation clusters. However, numerical experiments indicate that certain nonuniform cluster spacings promote a profound improvement in the even development of fracture growth. Identifying this effect relies on this new model's ability to capture the full hydrodynamical coupling between the simultaneously evolving HFs in their transition from radial to Perkins-Kern-Nordgren (PKN)-like geometries (Perkins and Kern 1961; Nordgren 1972)

Foreword and Conference Information [2017]

This is the front matter of the proceedings

Partnership Development Among Mental Health Organizations

Mental health organizations can play a key role in enhancing youths\u27 access to care by working together to bridge gaps in service delivery systems. This dissertation study examines partnerships among a network of children\u27s behavioral health organizations. The specific aims are to (1) describe and understand the network of partnerships among members of the Children\u27s Services Coalition, (2) assess the capacity of the system to provide coordinated service delivery, and (3) test how patterns of organizational characteristics influence conditions that facilitate and inhibit partnerships among the Children\u27s Service Coalition organizations. This dissertation is a predominantly quantitative cross-sectional network study of 36 children\u27s mental health organizations in St. Louis County that are members of the newly formed Children\u27s Services Coalition. Network data on relationships and archival data from IRS 990 forms were collected and used to explain how organizational characteristics might lead certain organizations to partner, but create conditions that simultaneously facilitate and hinder the degree to which organizations partner. Overall, the key findings describe partnership behavior at the network, small-group, and dyadic-level. First, children\u27s behavioral health organizations in the CSC maintain a complex set of partnerships, which are expected to grow as new opportunities emerge. Second, although partnerships are very common, the larger network may not be well coordinated as evidenced by the few systematic partnership patterns uncovered using descriptive network analysis techniques including sub-group analysis and blockmodeling. However there is potential for coordination at the sub-group level among small groups of similar organizations. Finally, at the dyadic-level, results of a path analysis demonstrate how similar competing organizations depend on one another for resources and benefit from their collaboration, which drives partnerships. Results suggest that organizational interests drive partnership development in this network, and bring together competing organizations that provide similar resources potentially as a strategy for managing competition, or creating efficiencies. This trend runs counter to system reform goals for bridging organizations with complementary services to facilitate access to quality care

Thematic relations as a cue to verb class: 2-year-olds distinguish unaccusatives from unergatives

Previous work shows that children use syntactic information to guide their hypotheses about verb meaning. Bunger & Lidz 2004 demonstrated that 2-year-olds map novel unaccusative verbs onto just the result subevent of a complex causative event and novel transitive verbs onto the entire causative event. We present data from a new preferential looking study demonstrating that 2-year-olds map novel unergative verbs onto the means subevent of a causative. We conclude that the interpretation of novel verbs is driven not only by the number of arguments in a given syntactic frame, but also by the semantic roles played by those arguments

Baseline Muscle Mass Is a Poor Predictor of Functional Overload-Induced Gain in the Mouse Model

This research was funded by the European Social Fund under the Global Grant measure. Grant VP1-3.1-ŠMM-07-K-02-057 was awarded to AL.Peer reviewedPublisher PD

Myostatin dysfunction is associated with reduction in overload induced hypertrophy of soleus muscle in mice

Acknowledgements This project was also supported by Marie Curie International Reintegration Grant 249156 (A. Lionikas) and the grants VP1-3.1-SMM-01-V-02-003 (A. Kilikevicius) and MIP-067/2012 (T. Venckunas) from the Research Council of Lithuania as well as the grant from the Ministry of Higher Education of Saudi Arabia (Y. Alhind). We wish also to thank Mrs Indre Libnickiene for her excellent technical assistance provided during the project.Peer reviewedPostprin

A low-rank matrix equation method for solving PDE-constrained optimization problems

PDE-constrained optimization problems arise in a broad number of applications such as hyperthermia cancer treatment and blood flow simulation. Discretization of the optimization problem and using a Lagrangian approach result in a large-scale saddle-point system, which is challenging to solve, and acquiring a full space-time solution is often infeasible. We present a new framework to efficiently compute a low-rank approximation to the solution by reformulating the KKT system into a Sylvester-like matrix equation. This matrix equation is subsequently projected onto a small subspace via an iterative rational Krylov method, and we obtain a reduced problem by imposing a Galerkin condition on its residual. In our work we discuss implementation details and dependence on the various problem parameters. Numerical experiments illustrate the performance of the new strategy also when compared to other low-rank approaches

Evaluation of Passive Integrated Transponders as a Marking Technique for Turkey Poults

Injectable, passive integrated transponders (PITs) were evaluated as a marking technique for newly hatched wild turkey (Meleagris gallopavo Linnaeus) poults. Seven of 12, 3-day-old domestic turkey poults received a PIT implant and a wing tag. A control group of five poults received only a wing tag. Two subcutaneous implant sites were evaluated, along the right side of the neck and in the area between the right inner thigh and breast. One of7 PITs failed or was expelled during the first week. Four scanning errors, in which the PIT was present yet not detected during the initial scanning attempt, occurred in 7 3 scanning attempts during a 12-week period. All scanning errors were abdominal implanted PITs. Two of 4 PITs implanted in the neck were destroyed during a shock test while none of the abdominal PITs were damaged. PITs seemed to be an efficient and reliable marking technique and have potential for field applications to wild turkeys

An Efficient and Accurate Approach for Studying the Heat Extraction from Multiple Recharge and Discharge Wells

In order to understand the thermal recovery Behavior of an engineered geothermal system (EGS), this paper develops a model in which fluid circulates in a single, planar hydraulic fracture with a constant hydraulic aperture via multiple recharging and discharging wells. The coupled equations for heat convection in the fracture plane and heat transfer into the rock are provided for steady and irrotational fluid flow conditions. By using velocity potentials and streamline functions, the temperature along a streamline is found to be only a function of the potential. By utilizing the Laplace transformation, the analytical solutions in the Laplace space for the temperature field are found, which are numerically inverted for time-domain results. Several examples with different arrangements of injection and production wells are investigated and the comparison with other published results is provided. The semi-analytical results demonstrate that the proposed model provides an efficient and accurate approach for predicting the temperatures of a multi-well reservoir system