Intercalation pattern and its impact on development of braided river reservoirs: A case of Fengcheng Oilfield, Junggar Basin, NW China

Abstract

Through comprehensive analysis of outcrops, core data and well logs, the type, formation mechanism and distribution pattern of intercalations in the braided river reservoirs of Fengcheng Oilfield, Junggar Basin are studied based on the reservoir architecture, and the inter-well distribution is predicted. The intercalations in Fengcheng Oilfield are divided into four types: intercalation in a bar, intercalation between bars, channel-bar transitional intercalation and chute. The intercalations include two lithologic types: argillaceous sandstone and fine grains. The intercalations are recognized in each individual well by core scale logging. Inter-well prediction is achieved by training image of intercalations established by multi-point statistics. The result indicates that the intercalations are not the uniform size and are scattered with lentoid distribution of various thicknesses. The horizontal wells in test area B are designed by the guidance of intercalation 3-D model, and practice indicates that the intercalation prediction is of great importance for improving oil production. Key words: braided river reservoir, intercalation, channel bar, multi-point statistics, inter-well intercalation prediction, Fengcheng Oilfield, Junggar Basin