Remaining Oil Distribution Law and Development Potential Analysis after Polymer Flooding Based on Reservoir Architecture in Daqing Oilfield, China.

Polymer flooding has drawn more and more attention in the world for its high incremental oil recovery factor and relative low costs compared with water flooding and other chemically enhanced oil recovery techniques. However, for many oilfields, such as Daqing Oilfield, China, that have already been flooded with polymers, how to further improve recovery remains a big problem. Traditional intralayer, interlayer and plane heterogeneity studies cannot accurately characterize the remaining oil distribution after polymer flooding.

Quantification of Methane-Induced Asphaltene Precipitation in a Multiple Contact Process.

A unique experiment design is proposed to study the asphaltene precipitation caused by multiple contact processes during gas injection. The newly proposed experiment quantified the asphaltene precipitation at different methane contact steps. Twenty times methane contacts and corresponding asphaltene precipitation states are measured using a light scattering setup under reservoir condition.

Study on Microscopic Distribution Characteristics of the Remaining Oil in Polymer-Flooded Reservoirs.

Polymer flooding is an effective enhanced oil recovery (EOR) technology used in Daqing Oilfield. Microscopic distribution of remaining oil in polymer-flooded reservoirs is more complicated in comparison with waterflooded reservoirs. In this paper, UV excitation, frozen section-laser confocal technology, and three-dimensional reconstruction technology were employed to investigate the distribution law and occurrence state of the microscopic remaining oil in polymer-flooded Daqing Oilfield.

Modified Flowing Material Balance Equation for Shale Gas Reservoirs.

To determine original gas-in-place, this study establishes a flowing material balance equation based on the improved material balance equation for shale gas reservoirs. The method considers the free gas in the matrix and fracture, the dissolved gas in kerogen, and the pore volume occupied by adsorbed phase simultaneously, overcoming the problem of incomplete consideration in the earlier models. It also integrates the material balance method with the flowing material balance method to obtain the average formation pressure, eliminating the problem with the previous method where shutting down of wells was needed to monitor the formation pressure.