Research On Seismic Acquisition Technology For Liaohe Complex Area

At present,the secondary 3D seismic exploration in Liaohe Depression has covered the entire area.But there are still as many as 1.32 billion tons of remaining reserves.The geological target of Liaohe Depression is complex such as deep buried hill,igneous rock oil and gas reservoirs.All kinds of obstacles on the ground such as towns,villages and rivers are interwoven in Liaohe Depression.These obstacles are so complex,which brings great difficulties to seismic acquisition shooting,receiving point arrangement and implementation.The poor quality of seismic data has become the bottleneck restricting the steady oil production of 10 million tons in Liaohe oilfield.The new seismic data acquisition in complex areas requires high signal-to-noise ratio,high resolution,high fidelity and high imaging precision.To overcome the problem of difficulties of seismic acquisition and poor quality of seismic data in complex areas of Liaohe Depression,this paper studied the optimization of seismic acquisition survey,shooting and receiving point arrangement.The main findings are as follows:(1)A set of seismic processing and interpretation results driven techniques of acquisition parameter optimization are proposed.By modeling and illumination,a method of receiving reflection information from whole target layer is developed,which ensures the balance of the target layer illumination energy.An optimum geometry design method aiming noise suppression is developed,which based on shot record FK spectrum analysis,as well as the migration noise analysis.It makes the evaluation of the 3D survey change from qualitative to quantitative.It also ensures the designed survey meets the requirements of pre-stack migration,and consolidates the ability of high fidelity and high accuracy of the data.(2)We developed the seismic acquisition method based on single point receiving and single excitation of vibroseis.Through theoretical research,scientific experiments and systematic analysis,the past combination receiving and combination excitation are gradually optimized to single point receiving and single vibration.It overcomes the restriction of complex surface conditions on combination excitation and combination receiving,which avoids combination effect and better meets the requirements of economic and technological integration.(3)The degenerated processing analysis of the actual high-density seismic acquisition data from the eastern exploration area in China was first carried out.Then we have revealed the variation law of the sensitivity of the seismic acquisition observation system parameters to the geological features,and proposed the optimization scheme of the observation system with single point receiving and single point excitation.The research results have been applied to several seismic data acquisition of complex areas in Liaohe Depression,which have achieved remarkable results.This study is practical and significant,and provides the technical support for tens millions tons of stable production in Liaohe Oilfield.Furthermore,it can provide technical reference for seismic acquisition in similar areas such as Bohai Bay Basin.