Thin-interbedded reservoirs prediction based on seismic sedimentology

Interference of thin-interbedded layers in seismic reflections has great negative impact on thin-interbedded reservoirs prediction.To deal with this,two novel methods are proposed that can predict the thin-interbedded reservoirs distribution through strata slices by suppressing the interference of adjacent layer with the help of seismic sedimentology.The plane distribution of single sand bodies in thin-interbedded reservoirs can be clarified.(1)The minimum interference frequency slicing method,uses the amplitude-frequency attribute estimated by wavelet transform to find a constant seismic frequency with the minimum influence on the stratal slice of target layer,and then an optimal slice corresponding the constant frequency mentioned above can be obtained.(2)The superimposed slicing method can calculate multiple interference coefficients of reservoir and adjacent layers of target geological body,and obtain superimposed slice by weighted stacking the multiple stratal slices of neighboring layers and target layer.The two proposed methods were used to predict the distribution of the target oil layers of 6 m thick in three sets of thin-interbedded reservoirs of Triassic Kelamayi Formation in the Fengnan area of Junggar Basin,Northwestern China.A comparison with drilling data and conventional stratal slices shows that the two methods can predict the distribution of single sand bodies in thin-interbedded reservoirs more accurately.

Characteristics of the crustal and mantle structures across Lhasa terrane

The Himalayan-Tibetan orogen is the youngest and arguably most spectacular of all the continent-continent collisional belts on the Earth. There are not only north-south extrusions but also east-west extensions in the Tibetan Plateau. All these phenomena are the results of the Indian plate subducting into the Eurasia plate about 70 Ma ago （Yin and Harrison, 2000）, but the deep dynamics mechanism is still an enigma. Exploring the crust and upper mantle structure of Tibetan plateau and revealing the process and the effect of collision are crucial for solving the puzzle of the Tibet uplift and the continent-continent collision. This research is based on the data from the 360km-long Dagze-Deqen-Domar profile, which can be divided into two sections. The Dagze-Deqen section traverses the Nyainqntanglha Mountains and the Yadong-Gulu rift, the biggest rift in the Tibet. The Deqen-Domar section crosses Lhasa terrane and Qiangtang terrane. We study the transverse density structure of the crust and mantle beneath the Dagze-Deqen-Domar profile using a joint gravity-seismic inversion technique in order to obtain the Moho and the asthenospheric configuration beneath the profile and understand the deep dynamics mechanism of the Yadong-Gulu rift.