Quality Control Of Geophones.docx

MAJOR PROJECT QUALITY CONTROL OF GEOPHONES MENTOR – PRESENTED BY – AISHWARYA PRAKASH DEPARTMENT OF COMPUTER SCIENCE MSC COMPUTER SCIENCE 4TH SEMESTER 2016MSCS001

CENTRAL UNIVERSITY OF RAJASTHAN, AJMER, RAJASTHAN

Quality control of Geophones: A Sensor Device Introduction All applications were developed primarily using Python and on Ubuntu OS architecture. My first task was to develop health check-ups of geophones which display the variations of resistance in geophones for the particular day using plotly which uses python and pandas which could serve the custom needs of geophysicist throughout the world. My second task was to develop a program which gives information about the system that the user is logged into which could serve the custom needs of users here at ONGC. Through the following pages of this report I attempt to summarise the projects I have developed over the course of my winter training. A geophone is a ground motion transducer that has been used by geophysicists and seismologists to convert ground movement into voltage. Any deviation in this measured voltage from the base line is regarded as seismic response, which is used for analysing the earth’s structure. Resonance frequency is the key factor in a geophone, and it has to be low for the measurement of low-frequency signals. On the other hand, geophone must exhibit high bandwidth to measure high-frequency signals as well. However, most of the currently available geophones include mechanical springs that decrease the performance of the device. Feeding back the output of geophone can vary the geophone’s sensitivity with respect to its frequency, and as a result low frequency signals are amplified. The resolution of geophone can be enhanced by controlling the position of proof mass. Working Principle A typical geophone consists of a mass suspended by means of mechanical springs. The geophone housing and the suspended mass start moving with the application of a velocity at frequencies lesser than the resonance frequency. The mass will remain stationary for frequencies greater than the resonance frequency. The movement of mass is based on either magnets or coils. The response of a coil/magnet geophone is proportional to the ground velocity. Applications Geophones are used for several industrial applications for vibration isolation purposes and absolute velocity sensing to achieve a high level of accuracy and precision. Geophone technology is employed to measure absolute velocity for lithographic and high-level inspection applications to determine payload disturbances caused by moving parts and other external disturbances. They are also used to position and control a complex lens system. Detection of leakage in oil and gas fields and earthquake prediction are also other major applications of geophones.

Motivation Seismic surveying is a vital part of exploring for oil and gas. That makes it critical to produce the energy we need to power our homes and businesses. Processing land seismic data has evolved significantly over the last ten years. The programmers there tried to map out this evolution and charted its development by means of the application of large high channelcount surveys.We believe that lessons learnt elsewhere in the world can be applied to good effect in India, especially if the potential of these techniques is understood and integrated into the design phase of the project. Land seismic surveys tend to be large entities, requiring hundreds of tons of equipment and employing anywhere from a few hundred to a few thousand people, deployed over vast areas for many months. A land seismic survey requires substantial logistical support. Time Lapse or 4D surveys are 3D seismic surveys repeated after a period of time. The 4D refers to the fourth dimension which in this case is time. Time Lapse surveys are acquired in order to observe reservoir changes during production and identify areas where there are barriers to flow that may not be detectable in conventional seismic. Time Lapse surveys consist out of a baseline survey and a monitor or repeat survey, acquired after the field was under production. Some of these surveys are collected using ocean-bottom cables because the cables can be accurately placed in their previous location after being removed. Better repetition of the exact source and receiver location leads to improved repeatability and better signal to noise ratios. A number of 4D surveys have also been set up over fields in which ocean bottom cables have been permanently deployed. To highlight the potential, we took noise removal techniques and integrated them into a real acquisition scenario.

Problem Definition Sound waves are bounced off underground rock formations and the waves that reflect back to the surface are captured by recording sensors. Analysing the time the waves take to return provides valuable information about rock types and possible gases or fluids in rock formations. This is similar to the use of ultrasound in medicine. The problem occurs when we are not able to detect the service of geophones, the sensors. The recordings of the geophones were resistance based and we have collected data at a particular time of the day and then analysis to find the errors. We have set the threshold as a parameter.

OBJECTIVES: The aim of the project is to visualize the resistance of the geophones and accordingly we can tell the status of the geophones i.e. good or bad. METHODOLOGY: 

Input consists of csv files having resistance of each geophone along with some other parameters like tilt etc. Each file represents the data taken for a particular time for a single day. Files are then cleaned and removed the unwanted columns and strings. Processed files are then parsed into Python’s Data Science Library and then they are plotted using Plotly.

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TECHNIQUES USED ARE: 

Python’s Data Science Library 

Pandas

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Matplotlib

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Plotly

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Python’s web framework Django.

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PostgresSql

MODULES:  Admin Authorizations for who is in the groups Authorizations for users  Users Can upload, view and download the files  Groups Authorized the users in the particular group EXPECTED RESULTS The unwanted data will be filtered out. The required data is mined to get visualized form. REFERENCES https://pesgb.conference-services.net/resources https://en.wikipedia.org/wiki/Reflection_seismology http://pluskid.org/slides/GTC2016-seismic.pdf