Multi-cycles Sequence Stratigraphy Analysis and the Application of Seismic Waveform Classification Technique for Sandstone Prediction in Shallow Lake Basin

The waveform analysis of seismic facies can be a good solution to the prediction of the sandbody problems. Previous researches and applications of Waveform seismic facies in the oil exploration mostly include the depositional systems and provenance systems; the relationship was not established between lithologic characteristic and waveforms. This article tries to establish the links between lithologic and seismic waveform at the context of shallow-water delta deposits.

Any change in physical parameters of seismic signal is always reflected in changes of seismic waveform. Seismic facies classification processing based on reflection changes in waveform; through self-organizing neural network algorithm, first of all, obtains model trace. Then utilizes the shape of seismic trace that is wave characteristic to contrast the actual seismic data in interval of layer, and describe the lateral variation of seismic signal.

According to the statistics of 22 drilled wells in pss2 in block A, HHK depression Neogene. Four modes of the combination of sandstone and mudstone are summarized: thin sandstone and mudstone, medium thickness of interbedded sandstone and mudstone, thick sandstone mudstone and large set of mudstone. According to the relationship between well trace waveform characteristics, waveform classification and combination mode of sandstone and mudstone in research area. Statistics found that the relationship existed have the following 4 categories:1. Low-frequency,medium-Strong amplitude Bell-shaped reflection wave: the anti-cycle of mudstone and fine sandstone, sandstone distributes intensively, single Layer thickness, channel and distal bar-distributary channel complex facies; 2. High-frequency,strong amplitude reflection wave backspin: mudstone with thin fine-grained sandstone compose Anti-cycle, delta front distal bar or shallow lake sand bar; 3. High-frequency,strong amplitude reflection wave topspin (higher wave peak): mudstone interbedded with medium-thick sandstone, distal bar and underwater distributary channel system; 4. Low-frequency, low amplitude Flat-shaped reflection waveform: large set of mudstone with gray, green and purple, the characteristics are large sets of mudstone lithology, shore-shallow lake facies. Based on establishment relationships of Lithologic characteristic and seismic wave, by way of waveform classification analysis, achieve excellent results by prediction of sandbody on the shallow-water basin.

AAPG Search and Discovery Article #90142 © 2012 AAPG Annual Convention and Exhibition, April 22-25, 2012, Long Beach, California