Single Trip Deployment of Multistage Completion Liners Through the Use of Interventionless Flotation Collars

Summary In difficult wellbores, the traditional method for deploying liners was to run drillpipe. The case studies discussed in this paper detail an alternative method to deploy liners in a single trip on the tieback string so the operator can reduce the overall costs of deployment. Previously, this was not often practical because the tieback string weight could not overcome the wellbore friction in horizontal applications. In each case, a flotation collar is required to ensure there is enough hookload for the deployment of the liner system. The flotation collars used are an interventionless design using a tempered glass barrier that shatters at a predetermined applied pressure. The glass debris is between 5 and 10 mm in diameter and can be easily circulated through the well without damaging downhole components. This is done commonly on a cemented liner and cemented monobore installations, but more rarely with openhole multistage completions. The authors of this paper have overseen thousands of cemented applications of this technology in Western Canada, the US onshore, Latin America, and the Middle East. For openhole multistage completions, the initial installation typically requires a ball drop activation tool at the bottom of the well to set the hydraulically activated equipment above. The effects of circulating the glass debris through one specific style of activation tool were investigated. Activation tools typically have a limited flow area and could prematurely close if the glass debris accumulates. Premature closing of the tool would leave drilling fluids in contact with the reservoir, potentially harming production. The testing was successfully completed, and the activation tool showed no signs of loading. This resulted in a full-scale trial in the field, where a 52-stage, openhole multistage fracturing liner was deployed using this technology. Through close collaboration with the operator, an acceptable procedure was established to safely circulate the glass debris and further limit the risk of prematurely closing the activation tool. This paper discusses the openhole and cemented multistage fracturing completion deployment challenges, laboratory testing, and field qualification trials for the single trip deployed system. It also highlights operational procedures and best practices when deploying the system in this fashion.

The Use of Euler Deconvolution Technique in the Estimation of Depth to Magnetic Source Bodies around the Schist Belt Parts of Kano State, Nigeria

Depth estimation of magnetic source bodies in parts of the Schist Belt of Kano, using Euler Deconvolution is presented in this paper. Detail ground magnetic survey was carried out using SCINTREX proton precession magnetometer to produce the Total Magnetic Intensity (TMI) map and consequently the residual map. The TMI ranges from 34,261 nT to 34,365 nT, while the residual field ranges from -160 nT to 115 nT. The depth estimate for contacts ranges from 6.5 m to 39.8 m, while that of dyke ranges from 8.9 m to 51.3 m. The depth estimation presented in this work is compared with the results of aeromagnetic study carried out in the same area and found to agree fairly well. Further, this also ensures the validity of aeromagnetic investigation in such applications. Keywords: Contacts, Dykes, Euler Deconvolution, Schist Belt. PACS: 91.25.F and 91.25.Rt.

TELOMERE BIOLOGY: TELOMERE STRUCTURE, FUNCTION AND RELATED DISEASES

Telomere is the special heterochromatin structure which caps the end of eukaryotic chromosome and ensures the faithful replication of genetic materials. It also provides the protection against DNA damage signals and ensures the genome integrity and stability. Telomerase complete its task by its unique nucleoprotein structure. Here in this paper detail about nucleoprotein structure and their function is included. Robustness of function of telomere across cell cycle is guaranteed by the interaction between telomere and its interacting proteins. Recent findings regarding telomere biology and cancer are also included in this paper. KEY WORDS: Telomere, DNA damage, cell cycle, cancer

Enhanced 32-Bit Adder Implementation using Different Configurations of Adders

Adders play a essential role with in the digital signal process systems. The 32-bit configuration is commonly used in few computerized systems and processors. In this paper, detail study about the implementation of 32-bit adders like Ripple Carry Adder (RCA), Carry Select adder (CSLA) and Carry Increment adder (CINA) is done for various configurational full adders using VHDL. The outcomes are acquired by executing VHDL in Xilinx ISE 14.5 with speed grade -5 of Spartan 3E family device.

Signal Integrity Analysis of High-Speed Differential Vias

In modern electronic systems, data rate is keeping increase, and Gbps becomes common, designing for reliable signal integrity becomes more and more important. In the high speed borad/package design, discontinuities are big concerns of signal integrity. A variety of sources lead to discontinuities and every source ought to be carefully treated. The signal via is one source of discontinuity that should not be overlooked. Vias can add jitter and reduce eye openings that can cause data misinterpretation by the receiver. This paper detail the antipad, pad and excess via stub effect on the vias. In each case, the impedance mismatch at the via transition can be minimized by optimizing a few parameters such as antipad radius, pad radius and excess via stub. The impacts of these parameters are investigated with the help for a full-wave 3D electromagnetic simulator.

The Design Practice and Implementation of a Flyback Converter

The design practice and simulation as well as implementation of a flyback converter are presented in this paper. Detail design considerations for each component in flyback converter are addressed and discussed. Based on the simulation results, a flyback converter is then realized and implemented. The experimental results show the verification for the design and implementation of the flyback converter. This paper concludes that the design of a flyback converter based on the proposed design practice, can reduce the development schedule duration and further alleviate the human resources need.

Development of the TIARA Hexapod: A Machine Tool Based on Parallel Kinematic Structures

The paper focuses on the TIARA Hexapod — a parallel kinematic machine tool that is being developed at McMaster University. The design uses fixed length struts, and an inclined layout for the motion axes that results in the mechanism resembling a ‘tiara’. In addition to the novelty of the design, these characteristics have several advantages from both a performance and economic perspective. The paper presents an overview of the development program for this machine tool, discussing issues related to design, modelling, inverse and forward kinematics, workspace, and dynamics analysis. Later sections of the paper detail the kinematic and dynamic models developed for the TIARA machine tool, and demonstrate their use for workspace analysis and the specification of actuator requirements.