24,439 research outputs found
Reservoir Simulation Model Using Water Injection and Water Alternating Gas Injection Techniques in KEYI Oilfield, Moglud Basin, Sudan
Simulation is only way to describe quantitatively the flow of multiple phases in a heterogeneous reservoir. Construction of reservoir simulation model requires a lot of data such as the types of rock and fluid properties. Enhancing the recovery of an oil reservoir is one of the major roles of any oil company. This is achieved by development of the oilfields by employing different techniques such as infill drilling, water injection, gas injection, water alternate gas (WAG) injection and even thermal methods. Reservoir simulation studies using water injection and water alternate gas injection for KEYI oil field, Muglad Basin, Sudan. The purpose of this simulation study is to determine the suitable method for increase and enhanced oil recovery. The simulation model was developed using two-phase, 3D and black oil options in ECLIPSE soft ware. Finally, the simulation result showed that water alternating gas technique is the best method to improve oil recovery from KEYI oil field, Muglad Basin, Sudan
Simple digital quantum algorithm for symmetric first order linear hyperbolic systems
This paper is devoted to the derivation of a digital quantum algorithm for
the Cauchy problem for symmetric first order linear hyperbolic systems, thanks
to the reservoir technique. The reservoir technique is a method designed to
avoid artificial diffusion generated by first order finite volume methods
approximating hyperbolic systems of conservation laws. For some class of
hyperbolic systems, namely those with constant matrices in several dimensions,
we show that the combination of i) the reservoir method and ii) the alternate
direction iteration operator splitting approximation, allows for the derivation
of algorithms only based on simple unitary transformations, thus perfectly
suitable for an implementation on a quantum computer. The same approach can
also be adapted to scalar one-dimensional systems with non-constant velocity by
combining with a non-uniform mesh. The asymptotic computational complexity for
the time evolution is determined and it is demonstrated that the quantum
algorithm is more efficient than the classical version. However, in the quantum
case, the solution is encoded in probability amplitudes of the quantum
register. As a consequence, as with other similar quantum algorithms, a
post-processing mechanism has to be used to obtain general properties of the
solution because a direct reading cannot be performed as efficiently as the
time evolution.Comment: 28 pages, 12 figures, major rewriting of the section describing the
numerical method, simplified the presentation and notation, reorganized the
sections, comments are welcome
Three Phase Relative Permeability Models for WAG Simulation
Imperial Users onl
Assessment and Evaluation of Sand Control Methods for a North Sea Field
Imperial Users onl
Matching on-the-fly in Sequential Experiments for Higher Power and Efficiency
We propose a dynamic allocation procedure that increases power and efficiency
when measuring an average treatment effect in sequential randomized trials.
Subjects arrive iteratively and are either randomized or paired via a matching
criterion to a previously randomized subject and administered the alternate
treatment. We develop estimators for the average treatment effect that combine
information from both the matched pairs and unmatched subjects as well as an
exact test. Simulations illustrate the method's higher efficiency and power
over competing allocation procedures in both controlled scenarios and
historical experimental data.Comment: 20 pages, 1 algorithm, 2 figures, 8 table
Predicting the outcomes of treatment to eradicate the latent reservoir for HIV-1
Massive research efforts are now underway to develop a cure for HIV
infection, allowing patients to discontinue lifelong combination antiretroviral
therapy (ART). New latency-reversing agents (LRAs) may be able to purge the
persistent reservoir of latent virus in resting memory CD4+ T cells, but the
degree of reservoir reduction needed for cure remains unknown. Here we use a
stochastic model of infection dynamics to estimate the efficacy of LRA needed
to prevent viral rebound after ART interruption. We incorporate clinical data
to estimate population-level parameter distributions and outcomes. Our findings
suggest that approximately 2,000-fold reductions are required to permit a
majority of patients to interrupt ART for one year without rebound and that
rebound may occur suddenly after multiple years. Greater than 10,000-fold
reductions may be required to prevent rebound altogether. Our results predict
large variation in rebound times following LRA therapy, which will complicate
clinical management. This model provides benchmarks for moving LRAs from the
lab to the clinic and can aid in the design and interpretation of clinical
trials. These results also apply to other interventions to reduce the latent
reservoir and can explain the observed return of viremia after months of
apparent cure in recent bone marrow transplant recipients and an
immediately-treated neonate.Comment: 8 pages main text (4 figures). In PNAS Early Edition
http://www.pnas.org/content/early/2014/08/05/1406663111. Ancillary files: SI,
24 pages SI (7 figures). File .htm opens a browser-based application to
calculate rebound times (see SI). Or, the .cdf file can be run with
Mathematica. The most up-to-date version of the code is available at
http://www.danielrosenbloom.com/reboundtimes
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