Search And Design On Marine Multiple Streamer Cables Seismic Data Acquisition And Recording System

It is well-known that the oil and natural gas are non-renewable which makes them important strategic resources. The increasing dependence of china on foreign oil production, which is over50%, has threatened our national security. However, due to the complex geological conditions, the oil and natural gas exploration level remains low. China’s reserve-production ratio is merely14:1which is far below the world average level of40:1. Nowadays, china onshore oil and gas exploration has reached to the middle stage, this make it an urgent task to exploit the rich offshore oil resources that were buried abundantly in deep sea.The Marine Seismic Data Acquisition and Recording System is believed to be the core equipment in offshore oil exploration. The specific system indicator determines not only its exploration capability but also its international competitiveness in the marine exploration. Therefore, developing our marine seismic data acquisition and recording system with independent intellectual property rights becomes the comprehensive requirements in terms of enhancing china’s national competition, technology competition, talent and market competition. Even though China has been lagged behind in the research and development of marine oil seismic exploration equipment for a long time, majority of our current domestic onshore and offshore equipments are imported, which has been seriously hampered the healthy development of our oil seismic exploration and oil industry. The rapid development in computer technology, network communication, electronic and information technology, along with material science, has provided us with excellent opportunity enabling us to achieve a leap in developing our seismic exploration equipments.In according with the above mentioned background,’863’, the national high-tech research program launched research plans in2001aim to develop offshore oil reservoir exploration equipment with Chinese self-owned intellectual property rights. From10/2001to12/2010, under close collaboration with the China Oilfield Services Limited, China Science and Technology University participated in several’863’ research projects. The first project is to develop the’Time-lapse marine Seismic Data Acquisition and Recording System (TMSDARS)’. In this work, we successfully realized the time-lapse seismic data acquisition and recording system adjustment, prototype design and marine experiments by using the piezoelectric ceramic detector and high density single-point detector. This system is proved to be low in cost while having high performance. The second project is the development of High-precision Deep Marine Seismic Data Acquisition System. With great effort we have developed the national first’sea bright’high-precision marine seismic acquisition system with dependent intellectual property rights. This development process went through two stages including the sample prototype and engineering prototype. Other than this, the overall performance and reliability of the system is further tested and verified with the long term practical on-sea work undertaken in Bo Hai and South Sea respectively between2009and2010. In this development process, it was aware that there are some important factors, apart from the simple electronic device and user interface, needed to consider based on our years of research and development experiences. In order to achieve the goal of designing better exploration system being competitive to the advanced large scale international marine exploration system, rather than merely blindly concentrated on pursuing high performance, it is necessary to analyze the system design concept so as to introduce the up to date applicable technology to the equipment design, this, hence, enables us to establish design foundation and scheme for specific instrument development. As a result, I setup the Research and Design on Marine Multi-Streamer Seismic Data Acquisition and Recording System (MMSDARS) as my Doctor’s thesis project.In this article, we first summarized the systematic composition of the marine seismic data acquisition and recording system, and its technology and operation characteristic according to the seismic exploration principle and offshore seismic acquisition technology. We then came up with the logic model of marine seismic data acquisition and recording system. This model consists the underwater seismic data acquisition subsystem and transmission subsystem, shipboard indoor data controlling subsystem and recording subsystem. These four subsystems work together to acts as four-layer logic model for seismic data acquisition and processing. We will describe in details these four subsystems separately in the following chapters. In the end of the article, we present the two examples of marine seismic multi-cable data acquisition and recording system designed according to the above introduced methods.This thesis is made up of seven chapters; the abstract of each chapter is introduced as followings:Chapter1IntroductionChapter Ⅰ begins with the introduction of the principle of seismic exploration, along with the methods and procedures undertaken in the marine seismic exploration to summarize the equipment required by the3D high resolution seismic exploration. This is followed by the description of the history and development prospective of seismic exploration equipment. In the end, the importance of this research project and content is presented.Chapter2Technology of marine seismic exploration In this chapter, we will analyze the geological condition of marine seismic and introduce systematically the technology related to seismic exploration in terms of the sources, GPS and data collecting.Chapter3Brief Description of MMSDARS DesignIn this chapter, we present the necessity of carrying out3D seismic exploration and relevant design scheme for achieving this goal. We think the design of MMSDARS should target to meet the need of oil exploration and development of physical geography with the help of proper technologies rather than focusing on the pursuit of new technologies and high performances. This model is the basic subject of discussion for the continued chapters and is regarded as guidline for practical system design. Finally, some difficult point came crossed in the design process are put forward along with the basic index requirement for system design.Chapter4Design of Acquisition and Transmission System (ATS) This chapter introduces the front-end seismic acquisition sub-system that converts analog seismic signal to digital signals and the seismic data transmission sub-system that transfers digital data from data acquisition modules to indoor recording system. The acquisition sub-system is composed of sensors, analog pre-processing and digital processing circuits. It is the choke point and restricts the key performances of the ATS, such as dynamic range and total harmonic distortion. The transmission sub-system has a multi-level architecture and uses topologies of pipeline, which can enhance limits of the data transmission distance and speed, hence, enabling the feasibility of large coverage area3D seismic exploration. Additionally, the design plan of the system synchronization and cables power supply are also presented.Chapter5Design of Recording and Controlling System This chapter discussed in details the design scheme and realization of the multi-cable indoor high-speed recording and controlling system in terms of the in-time data transmission, receiving, processing and recording, in addition to the in-time monitor function regarding the overall system control and data acquisition process. The design scheme composed of two aspects including system hardware design and software design on three workstations. In the end of this chapter mass data record and record formats of seismic data on tape and RAID is also introduced.Chapter6:MMSDARS Design Examples This chapter describes two design examples of MMSDARS. One has4streamer cables and another has16streamer cables. The former example is actual system and has been tested and accepted by related departments. The latter one is still an experimental prototype and has not been given sea onfield testing.Chapter7:Conclusions and Outlook This chapter summarizes the innovation and progress achieved in the development of MMSDARS and provides insights into the future development prospective of the marine seismic data acquisition sytem. Some meaningful future work is also pointed out in end of the chapter.