Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield,...Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield, Subei Basin, China, to investigate the hierarchical muddy baffles developed on lacustrine delta fronts and their precise cross-well correlation.According to the theories on allogenic and autogenic cycles as well as the genesis and scales of muddy baffles, five orders of muddy baffles were classified, which provided various degrees of difficulty when attempting interwell correlation. Under the guidance of a reliable stratigraphic model, the precise cross-well correlation of muddy baffles could be achieved and the key point of establishment of this stratigraphic model was to calculate foreset angles of hierarchical muddy baffles during deposition. During calculation, the relationships between sediment flow direction, higher-order strata dipping direction,well types and well trajectory direction should all be taken into consideration and some other angles（referred to here as θ1,θ2 and θ3） should also be measured. Such new methods of cross-well correlation for hierarchical muddy baffles could greatly reduce the uncertainties and multiple solutions, which in turn would be significant for efficient development and oil recovery enhancement in the reservoirs.展开更多
基金supported by an Open Fund of State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation (Southwest Petroleum University, PLN1503)the National Natural Science Foundation of China (Nos. 41602145, 41402125, and 41602117)Scientific Research Starting Project of SWPU (No. 2014QHZ008)
文摘Muddy baffles are one of the major geological factors controlling the underground fluid flow as well as the remaining oil distribution. This study used detailed drilling data from the E1f1 reservoir in the X Oilfield, Subei Basin, China, to investigate the hierarchical muddy baffles developed on lacustrine delta fronts and their precise cross-well correlation.According to the theories on allogenic and autogenic cycles as well as the genesis and scales of muddy baffles, five orders of muddy baffles were classified, which provided various degrees of difficulty when attempting interwell correlation. Under the guidance of a reliable stratigraphic model, the precise cross-well correlation of muddy baffles could be achieved and the key point of establishment of this stratigraphic model was to calculate foreset angles of hierarchical muddy baffles during deposition. During calculation, the relationships between sediment flow direction, higher-order strata dipping direction,well types and well trajectory direction should all be taken into consideration and some other angles（referred to here as θ1,θ2 and θ3） should also be measured. Such new methods of cross-well correlation for hierarchical muddy baffles could greatly reduce the uncertainties and multiple solutions, which in turn would be significant for efficient development and oil recovery enhancement in the reservoirs.
