Well Control in Extended Reach Drilling (ERD) Well by Using WELLPLAN Software

The oil and gas industry has developed rapidly by introduced new various technologies. Directional, horizontal, Extended Reach Drilling (ERD) and multilateral wells has been used in the industry for economical and technical reasons. Even though technologies are well developed in the last decade, but these wells still have high levels of risk in drilling and completion. Well control is one of the important issues because improper well control will lead to a blowout which is the most feared operational hazards and expensive cost. The key elements for the success and further development of ERD projects are the ability to continue developing new technology while at the same time adopting a technical limit approach to performance delivery. For this study, the project focused on well control in ERD well by using Halliburton‟s software, WELLPLAN. WELLPAN is very useful software which is provides various functionalities such as torque drag analysis, analyze hydraulics, analyze surge/swab pressures and ECD‟s, investigate well control and etc. This project is focused on investigate well control using the Well Control Analysis Module. The Well Control module can be used to determined predicted kick type, estimate influx volume and kick tolerance, evaluate pressure and generate kill sheet. Besides, the theoretical calculations also were performed to compare the results with WELLPLAN. Two equations are identical to find the suitable kill rate. Based on this study with literature review, well control procedures for extended-reach wells are as follows: Once a kick is detected and confirmed, perform a “hard” shut-in of the well. When the pressure is stabilized, record SIDPP, SICP and pit gain and start circulate immediately using the Driller‟s Method. In order to remove the gas from the horizontal section, the kill rate should be 1/3 to ½ of the rate in drilling circulation flowrate

Affinely adjustable robust Volt/VAr control without centralized computations

This paper proposes a completely non-centralized Volt/VAr control (VVC) algorithm for active distribution networks which are faced with voltage magnitude violations due to the high penetration of solar photovoltaics (PVs). The proposed VVC algorithm employs a two-stage architecture where the settings of the classical voltage control devices (VCDs) are decided in the first stage through a distributed optimization engine powered by the alternating direction method of multipliers (ADMM). In contrast, the PV smart inverters are instructed in the second stage through linear Q(P) decision rules - which are computed in a decentralized manner by leveraging robust optimization theory. The key to this non-centralized VVC routine is a proposed network partition methodology (NPM) which uses an electrical distance metric based on node Q-V 2 sensitivities for computing an intermediate reduced graph of the network, which is subsequently divided into the final partitions using the spectral clustering technique. As a result, the final network partitions are connected, stable, close in cardinality, contain at least one PV inverter for zonal reactive power support, and are sufficiently decoupled from each other. Numerical results on the UKGDS-95 bus system show that the non-centralized solutions match closely with the centralized robust VVC schemes, thereby significantly reducing the voltage violations compared to the traditional deterministic VVC routines

An Assessment of Customer's Preferences on the Selection of Takaful Over Conventional: a Case of Saudi Arabia

This paper aims at assessing the motivational factors that influence the customer's preferences of Takaful over conventional insurance. The customers' information about the Takaful products and services based on sharia are identified in order to enable them differentiate Takaful and conventional insurance. The research uses mixed method of data collection. This comprises of questionnaires and in-depth interviews with the respondents from four selected Takaful industries in Saudi Arabia. The questionnaires were analysed using simple percentages and for the interviews, thematic analyses were used. Based on the findings of the study, the customer's preferences on the selection of Takaful over conventional insurance include protection of Takaful product by sharia, support from the government. Similarly, the absence of risk incurred or transferred to participants, funds contributed in the spirit of brotherhood for all members. Moreover, another customer's preferences is that contributions (tabarru') are invested in non-interest based capitalization by the Takaful agents and profits are shared according to individual contributions. Based on Takaful, donations are established at the pooling system in line with sharia and they are formed on the bases of sympathy, consciousness of the idea of tabarru' as well as abstaining from gharar, maysir and riba

Selective spin coupling through a single exciton

We present a novel scheme for performing a conditional phase gate between two spin qubits in adjacent semiconductor quantum dots through delocalized single exciton states, formed through the inter-dot Foerster interaction. We consider two resonant quantum dots, each containing a single excess conduction band electron whose spin embodies the qubit. We demonstrate that both the two-qubit gate, and arbitrary single-qubit rotations, may be realized to a high fidelity with current semiconductor and laser technology.Comment: 5 pages, 3 figures; published version, equation formatting improved, references adde

Dissipation enhanced vibrational sensing in an olfactory molecular switch

Motivated by a proposed olfactory mechanism based on a vibrationally-activated molecular switch, we study electron transport within a donor-acceptor pair that is coupled to a vibrational mode and embedded in a surrounding environment. We derive a polaron master equation with which we study the dynamics of both the electronic and vibrational degrees of freedom beyond previously employed semiclassical (Marcus-Jortner) rate analyses. We show: (i) that in the absence of explicit dissipation of the vibrational mode, the semiclassical approach is generally unable to capture the dynamics predicted by our master equation due to both its assumption of one-way (exponential) electron transfer from donor to acceptor and its neglect of the spectral details of the environment; (ii) that by additionally allowing strong dissipation to act on the odorant vibrational mode we can recover exponential electron transfer, though typically at a rate that differs from that given by the Marcus-Jortner expression; (iii) that the ability of the molecular switch to discriminate between the presence and absence of the odorant, and its sensitivity to the odorant vibrational frequency, are enhanced significantly in this strong dissipation regime, when compared to the case without mode dissipation; and (iv) that details of the environment absent from previous Marcus-Jortner analyses can also dramatically alter the sensitivity of the molecular switch, in particular allowing its frequency resolution to be improved. Our results thus demonstrate the constructive role dissipation can play in facilitating sensitive and selective operation in molecular switch devices, as well as the inadequacy of semiclassical rate equations in analysing such behaviour over a wide range of parameters.Comment: 12 pages, 6 figures, close to published version, comments welcom

Post-acute COVID-19 neuropsychiatric symptoms are not associated with ongoing nervous system injury

A proportion of patients infected with severe acute respiratory syndrome coronavirus 2 experience a range of neuropsychiatric symptoms months after infection, including cognitive deficits, depression and anxiety. The mechanisms underpinning such symptoms remain elusive. Recent research has demonstrated that nervous system injury can occur during COVID-19. Whether ongoing neural injury in the months after COVID-19 accounts for the ongoing or emergent neuropsychiatric symptoms is unclear. Within a large prospective cohort study of adult survivors who were hospitalized for severe acute respiratory syndrome coronavirus 2 infection, we analysed plasma markers of nervous system injury and astrocytic activation, measured 6 months post-infection: neurofilament light, glial fibrillary acidic protein and total tau protein. We assessed whether these markers were associated with the severity of the acute COVID-19 illness and with post-acute neuropsychiatric symptoms (as measured by the Patient Health Questionnaire for depression, the General Anxiety Disorder assessment for anxiety, the Montreal Cognitive Assessment for objective cognitive deficit and the cognitive items of the Patient Symptom Questionnaire for subjective cognitive deficit) at 6 months and 1 year post-hospital discharge from COVID-19. No robust associations were found between markers of nervous system injury and severity of acute COVID-19 (except for an association of small effect size between duration of admission and neurofilament light) nor with post-acute neuropsychiatric symptoms. These results suggest that ongoing neuropsychiatric symptoms are not due to ongoing neural injury.</p

Entanglement distribution for a practical quantum-dot-based quantum processor architecture

We propose a quantum dot (QD) architecture for enabling universal quantum information processing. Quantum registers, consisting of arrays of vertically stacked self-assembled semiconductor QDs, are connected by chains of in-plane self-assembled dots. We propose an entanglement distributor, a device for producing and distributing maximally entangled qubits on demand, communicated through in-plane dot chains. This enables the transmission of entanglement to spatially separated register stacks, providing a resource for the realization of a sizeable quantum processor built from coupled register stacks of practical size. Our entanglement distributor could be integrated into many of the present proposals for self-assembled QD-based quantum computation (QC). Our device exploits the properties of simple, relatively short, spin-chains and does not require microcavities. Utilizing the properties of self-assembled QDs, after distribution the entanglement can be mapped into relatively long-lived spin qubits and purified, providing a flexible, distributed, off-line resource. © IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

Well Control in Extended Reach Drilling (ERD) Well by Using WELLPLAN Software

The oil and gas industry has developed rapidly by introduced new various technologies. Directional, horizontal, Extended Reach Drilling (ERD) and multilateral wells has been used in the industry for economical and technical reasons. Even though technologies are well developed in the last decade, but these wells still have high levels of risk in drilling and completion. Well control is one of the important issues because improper well control will lead to a blowout which is the most feared operational hazards and expensive cost. The key elements for the success and further development of ERD projects are the ability to continue developing new technology while at the same time adopting a technical limit approach to performance delivery. For this study, the project focused on well control in ERD well by using Halliburton‟s software, WELLPLAN. WELLPAN is very useful software which is provides various functionalities such as torque drag analysis, analyze hydraulics, analyze surge/swab pressures and ECD‟s, investigate well control and etc. This project is focused on investigate well control using the Well Control Analysis Module. The Well Control module can be used to determined predicted kick type, estimate influx volume and kick tolerance, evaluate pressure and generate kill sheet. Besides, the theoretical calculations also were performed to compare the results with WELLPLAN. Two equations are identical to find the suitable kill rate. Based on this study with literature review, well control procedures for extended-reach wells are as follows: Once a kick is detected and confirmed, perform a “hard” shut-in of the well. When the pressure is stabilized, record SIDPP, SICP and pit gain and start circulate immediately using the Driller‟s Method. In order to remove the gas from the horizontal section, the kill rate should be 1/3 to ½ of the rate in drilling circulation flowrate