A Case Study on Blowout and Its Control in Krishna-Godavari (KG) Basin, East Coast of India: Safety and Environmental Perspective

Major blowouts in Krishna-Godavari (KG) basin have led to number of risks related to loss of human lives, environmental pollution and loss of material assets. The geological complexity of the field and the presence of over pressure zones, mainly in East Godavari sub-basin, particularly in the wells at Amalapuram, Razole and Narsapur have led to major disasters in the past years. Therefore, an attempt has been made to identify the most possible causes of these disasters and to propose a safe drilling procedure to prevent these disasters in the upcoming ventures. This paper highlights the case study of a blowout occurred in KG basin in East Coast of India. An analysis of the blowout was carried out which includes well configuration and details, mechanical equipment used for controlling the blowout, firefighting procedures, financial losses incurred. The effect of exploration and production of oil and gas on the property and environment were also discussed. Efficient drilling and safety procedures were recommended to prevent further blowouts in future. The recommendations presented will be of utmost importance for oil and gas operators and service companies to take necessary steps in future drilling operations in over pressured formations of KG basin to prevent loss to personnel, property and damage to the environment. Keywords: Blowout, Overpressures, Firefighting, Safety Procedures, Environmental Impact

A Case Study on Blowout and Its Control in Krishna-Godavari (KG) Basin, East Coast of India: Safety and Environmental Perspective

Major blowouts in Krishna-Godavari (KG) basin have led to number of risks related to loss of human lives, environmental pollution and loss of material assets. The geological complexity of the field and the presence of over pressure zones, mainly in East Godavari sub-basin, particularly in the wells at Amalapuram, Razole and Narsapur have led to major disasters in the past years. Therefore, an attempt has been made to identify the most possible causes of these disasters and to propose a safe drilling procedure to prevent these disasters in the upcoming ventures. This paper highlights the case study of a blowout occurred in KG basin in East Coast of India. An analysis of the blowout was carried out which includes well configuration and details, mechanical equipment used for controlling the blowout, firefighting procedures, financial losses incurred. The effect of exploration and production of oil and gas on the property and environment were also discussed. Efficient drilling and safety procedures were recommended to prevent further blowouts in future. The recommendations presented will be of utmost importance for oil and gas operators and service companies to take necessary steps in future drilling operations in over pressured formations of KG basin to prevent loss to personnel, property and damage to the environment. Keywords: Blowout, Overpressures, Firefighting, Safety Procedures, Environmental Impact

Partially spin polarized quantum Hall effect in the filling factor range 1/3 < nu < 2/5

The residual interaction between composite fermions (CFs) can express itself through higher order fractional Hall effect. With the help of diagonalization in a truncated composite fermion basis of low-energy many-body states, we predict that quantum Hall effect with partial spin polarization is possible at several fractions between $\nu=1/3$ and $\nu=2/5$. The estimated excitation gaps are approximately two orders of magnitude smaller than the gap at $\nu=1/3$, confirming that the inter-CF interaction is extremely weak in higher CF levels.Comment: 4 pages, 3 figure

Accessibility to transit station in multi modal transport framework for Delhi

Recently, Multi Modal Transit Station has been recognized as a symbol of ‘Urban Identity’ and ‘Urban Mobility’ in Delhi which integrates built environment with multiple modes and provides an important link to complete the journey. It is either as a single station or an interchange hub, accessed by human, mechanical and vehicular system. Hence, it is important that such transit station must meet minimal level of service and be a part of overall efforts to improve transit services for increasing rider ship. In this context, Multi Modal Oriented Design (M2OD) is used which defines neighborhood character in design and provides mobility friendly environment. It also encourages a mix of mobility options to cater needs of both present and future travel demands. Further, the role and responsibilities of transit operators, facilitators and users are crucial to extend better accessibility to transit station

Edge reconstructions in fractional quantum Hall systems

Two dimensional electron systems exhibiting the fractional quantum Hall effects are characterized by a quantized Hall conductance and a dissipationless bulk. The transport in these systems occurs only at the edges where gapless excitations are present. We present a {\it microscopic} calculation of the edge states in the fractional quantum Hall systems at various filling factors using the extended Hamiltonian theory of the fractional quantum Hall effect. We find that at $\nu=1/3$ the quantum Hall edge undergoes a reconstruction as the background potential softens, whereas quantum Hall edges at higher filling factors, such as $\nu=2/5, 3/7$, are robust against reconstruction. We present the results for the dependence of the edge states on various system parameters such as temperature, functional form and range of electron-electron interactions, and the confining potential. Our results have implications for the tunneling experiments into the edge of a fractional quantum Hall system.Comment: 11 pages, 9 figures; minor typos corrected; added 2 reference

Universal flow diagram for the magnetoconductance in disordered GaAs layers

The temperature driven flow lines of the diagonal and Hall magnetoconductance data (G_{xx},G_{xy}) are studied in heavily Si-doped, disordered GaAs layers with different thicknesses. The flow lines are quantitatively well described by a recent universal scaling theory developed for the case of duality symmetry. The separatrix G_{xy}=1 (in units e^2/h) separates an insulating state from a spin-degenerate quantum Hall effect (QHE) state. The merging into the insulator or the QHE state at low temperatures happens along a semicircle separatrix G_{xx}^2+(G_{xy}-1)^2=1 which is divided by an unstable fixed point at (G_{xx},G_{xy})=(1,1).Comment: 10 pages, 5 figures, submitted to Phys. Rev. Let

The effect of higher derivative correction on η/s\eta /s and conductivities in STU model

In this paper we study the ratio of shear viscosity to entropy, electrical and thermal conductivities for the R-charged black hole in STU model. We generalize previous works to the case of a black hole with three different charges. Actually we use diffusion constant to obtain ratio of shear viscosity to entropy. By applying the thermodynamical stability we recover previous results. Also we investigate the effect of higher derivative corrections.Comment: revised versio

Calculating the jet-quenching parameter in STU background

In this paper we use the AdS/CFT correspondence to compute the jet-quenching parameter in a N=2 thermal plasma. We consider the general three-charge black hole and discuss some special cases. We add a constant electric field to the background and find the effect of the electric field on the jet-quenching parameter. Also we include higher derivative terms and obtain the first-order correction for the jet-quenching parameter.Comment: 17 pages, 3 figures, revised versio

Activated Random Walkers: Facts, Conjectures and Challenges

We study a particle system with hopping (random walk) dynamics on the integer lattice $\mathbb Z^d$. The particles can exist in two states, active or inactive (sleeping); only the former can hop. The dynamics conserves the number of particles; there is no limit on the number of particles at a given site. Isolated active particles fall asleep at rate $\lambda > 0$, and then remain asleep until joined by another particle at the same site. The state in which all particles are inactive is absorbing. Whether activity continues at long times depends on the relation between the particle density $\zeta$ and the sleeping rate $\lambda$. We discuss the general case, and then, for the one-dimensional totally asymmetric case, study the phase transition between an active phase (for sufficiently large particle densities and/or small $\lambda$) and an absorbing one. We also present arguments regarding the asymptotic mean hopping velocity in the active phase, the rate of fixation in the absorbing phase, and survival of the infinite system at criticality. Using mean-field theory and Monte Carlo simulation, we locate the phase boundary. The phase transition appears to be continuous in both the symmetric and asymmetric versions of the process, but the critical behavior is very different. The former case is characterized by simple integer or rational values for critical exponents ($\beta = 1$, for example), and the phase diagram is in accord with the prediction of mean-field theory. We present evidence that the symmetric version belongs to the universality class of conserved stochastic sandpiles, also known as conserved directed percolation. Simulations also reveal an interesting transient phenomenon of damped oscillations in the activity density

Fermion Chern Simons Theory of Hierarchical Fractional Quantum Hall States

We present an effective Chern-Simons theory for the bulk fully polarized fractional quantum Hall (FQH) hierarchical states constructed as daughters of general states of the Jain series, {\it i. e.} as FQH states of the quasi-particles or quasi-holes of Jain states. We discuss the stability of these new states and present two reasonable stability criteria. We discuss the theory of their edge states which follows naturally from this bulk theory. We construct the operators that create elementary excitations, and discuss the scaling behavior of the tunneling conductance in different situations. Under the assumption that the edge states of these fully polarized hierarchical states are unreconstructed and unresolved, we find that the differential conductance $G$ for tunneling of electrons from a Fermi liquid into {\em any} hierarchical Jain FQH states has the scaling behavior $G\sim V^\alpha$ with the universal exponent $\alpha=1/\nu$, where $\nu$ is the filling fraction of the hierarchical state. Finally, we explore alternative ways of constructing FQH states with the same filling fractions as partially polarized states, and conclude that this is not possible within our approach.Comment: 10 pages, 50 references, no figures; formerly known as "Composite Fermions: The Next Generation(s)" (title changed by the PRB thought police). This version has more references and a discussion of the stability of the new states. Published version. One erroneous reference is correcte