Land multi-line recording techniques: selected case histories from the People's Republic of China and Western Australia

Abstract

The A-Er-Shan Field, in the Inner Mongolia Region of PRC is a buried hill type structure. The oilfield's nature is such that a detailed grid of 2-D seismic could not adequately map the producing horizons. A 3-D seismic survey of the oilfield was required to provide the proper spatial sampling of the productive horizons to both map the numerous faults in the field and to migrate dipping horizons to their proper spatial position. Thevenard Island in Western Australia is an environmentally sensitive surface feature 6.0 km long by 1.5 km wide within the hydrocarbon rich and environmentally sensitive NW shelf environment. After extensive pre-survey modelling and subsurface fold simulations optimum field geometry was established for each survey using a multi-line Swathe configuration. Infield experimentation was used to determine relevant source, receiver arrays and modelled Varisweep? parameters utilising the Vibroseis seismic source. Following final processing, objectives of vertical and spatial resolution were attained along with significant improvements in S/N over previously recorded data.