Electro Magnetic Wireline Retrievable-Surface Controlled Subsurface Safety Valve: A New Backup For Surface Controlled Subsurface Safety Valve To Avoid WorkOver

Development of a Retrievable Subsurface Accelerometer

This paper describes the development of a Retrievable Subsurface Accelerometer (RSA) for the NSF George E. Brown, Jr., Network for Earthquake Engineering Simulation (NEES) project at UCLA. The RSA was developed to obtain subsurface vibration data during forced-vibration experiments and aftershock events. The RSA can be rapidly installed using a CPT truck and subsequently retrieved using structu...

Invasive Surface and Subsurface Data

A Symmetric Safety Valve

How to set policy in the presence of uncertainty has been central in debates over climate policy. Concern about costs has motivated the proposal for a cap-and-trade program for carbon dioxide, with a “safety valve” that would mitigate against spikes in the cost of emission reductions by introducing additional emission allowances into the market when marginal costs rise above the specified allow...

A new plan to connect aluminum tubes of subsurface structures

  In this study, a new method for joining aluminum tubes in subsurface structures using steel converting and aluminum welding are presented and reviewed. But near the weld area is under high thermal cycle and will cause residual stresses in heat affected zone. Therefore for assessment of proposed connection from the perspective of residual stress by using the finite element method welding of tu...

Rough Surface Estimation for Subsurface Imaging

In this paper a distance measurement based reflection point terrain estimation method (RPTEM) for characterizing two-dimensional (2-D) rough surfaces is presented. The method is based on the analysis of timedomain field data obtained by GPR system with Synthetic Aperture Radar (SAR) scan over 2-D rough ground surfaces. The distance from each antenna position to the ground surface is established...