Sand Detection Using Integrated AVA and Rock Property Analysis: Applications in Horizontal Well Drilling

An integrated methodology to characterize sandstone reservoirs in offshore Arabian Gulf oil fields is described in this paper. The methodology incorporates amplitude vs. angle (AVA) inversion and rock property analyses with the objective of defining optimum elastic properties to separate sandstone from shale and limestone. A set of elastic property cutoffs is determined from the rock property analysis and used to interrogate the AVA volumes to detect sandstone reservoirs and map their lateral and vertical distributions. The detected AVA sand images have been used to support planning and drilling of more than 100 wells in the last five years. Several examples from recent drilling results will be shared to show the application and limitation of the technique as well as recommendations for future improvements.