Major Chinese field evaluated using combined seismic and well logging methods

In Lunnan field, an Ordovician carbonate buildup in the Tarim basin of western China, the reservoir was identified and characterized using a combination of seismic techniques and well logging methods. The seismic techniques included 3D seismic visualization and seismic attribute analyses such as coherence and root-mean-square amplitude. Well logging methods used were Formation Micro-Imaging (FMI), Electric Micro-Imaging (EMI) and Dipole Sonic Imaging (DSI). The research indicated that the Lunnan Ordovician buried hill is an oil-producing reservoir that developed under the unconformity, with a thickness of 0-150 m. The slope of the buried hill was determined to be the best location for development of the reservoir. Using the above methods, the exploration success rate was increased by 117%, and crude oil production increased to over 300 times its pre-characterization rate. The reservoir characterization also enabled a major upward re-evaluation of Lunnan field’s in situ resources.