The article describes an approach to the study of the effect of low-volume chemical enhanced oil recovery (EOR) methods using the control group method on the example of the Vankorskoye oil-gas-condensate field. The study involved comparing the performance indicators of the producing wells in the waterflooding blocks that had their injection wells treated with cross-linked polymer compounds and the performance indicators of wells in neighboring waterflooding blocks with similar properties that did not have their injection wells subjected to such treatments. The study has been motivated by the general features of the low-volume chemical EOR methods: they have an effect that is small relative to the flow rates of the reactive wells; this effect is not bound to the wells treated; and the effect manifests itself gradually over a sufficiently long time. These features lead to the possibility of a systematic error significant in the scale of the effect of the low-volume chemical EOR methods when assessing said effect by predicting watercut using standard displacement characteristics for a specific reservoir. The choice of the control group method in addition to the means of instrumental control and assessment by displacement characteristics has been necessitated by the relative simplicity of this approach, as well as the possibility of its application without additional costs, using already available field data. Through the application of this method, the real effect of the low-volume chemical EOR method for the Vankorskoye field has been verified. The absence of a significant systematic error in the forecast of watercut for the displacement characteristics used in the methodology adopted by Rosneft Oil Company has been confirmed. As a result, it became possible to proceed with the full-scale implementation of the low-volume chemical EOR method throughout the Vankorskoye field.
References
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