Key Technologies Of Large Scale Seismic Survey System Design

Oil is non-renewable resources and is an important strategic material. High-precision,high-resolution,high-density seismic exploration technology and equipment is the key of exploration of mineral resources such as oil,gas,coal and coal-bed methane.Conventional seismic exploration equipments currently in used are all imported from abroad,technologically can not meet the need of seismic exploration under the complicated geological conditions in China.As the accelerated process of development and usage of China's oil and gas resources,oil and gas exploration is faced with serious constraints of key technologies under conditions such as deep hidden reservoir in east of China,complex underground structure in west of China and rough seabed under sea.This resulted in increased investment risk,slow increase in reserves,low success rate,etc,affecting the sustainable development of oil and gas resources.Especially with the exploration target areas from simple to complex regions,the exploration of the status of a lower level of skills has become the weaknesses of development of China's oil and gas industry.At the same time,our country and Western oil companies are competing in the international oil and gas exploration market.Introducing key technologies in oil and gas exploration to China are restricted by the foreign oil companies.Therefore,in 2006,China National Petroleum established the project "large scale land-based seismic data acquisition recording system" as one of the major special project in the Eleventh Five-Year plan.The goal is to develop a land-based seismic exploration system with the same functions and indicators to imported systems.Our laboratory was assumed the researching and developing tasks of "Seismic data acquisition system based on LRE-PHY".I was in charge of the R & D tasks of the data transmission part of the system.After the completion of the former project,in 2008,our laboratory in collaboration with the Institute of Geology and Geophysics of Chinese Academic of Science,launched the investment of key technologies in million-channel all-digital seismic acquisition system.I take charge in the pre-research in wireless transmission and some related techniques of the system.This paper is divided into the following six chapters:Chapter 1 begins with the methods of oil seeking,introduces the fundament of seismic exploration,and analyzes the requirement of seismic exploration equipments. Then the history and present status of development of seismic exploration equipments is introduced.At last the key points of this thesis are briefly introduced.Chapter 2 introduced the system of "Seismic data acquisition system based on LRE-PHY",of which the development has been completed.Introduction begins with the requirement of the system.Then the system is presented from the overall framework to functional blocks.And some of the key techniques are introduced.Chapter 3 analyzes the direction of the development of seismic instruments.Here lists some latest equipment of Western Companies,analysis their technical characteristics.Chapter 4 mainly discusses key technologies involved in the introduction of wireless transmission into the wired network in the million-channel seismic data acquisition system,including the choosing of wireless transmission standards, deciding of network topology,positioning wireless nodes,clock synchronizing in wireless system,routing in Ad-hoc networks,et al.Chapter 5 makes some experiments and simulations to verify the theory raised in Chapter 4.There is experiment on clock synchronizing based on CDR,experiment on distance measurement based on RSSI,and simulation on AODV in NS-2.Chapter 6 is the summary of the papers,made clear the problems with further in-depth research,to improve the direction.