Dynamic Fluid Diversion with Advanced Pressure Monitoring Technique – New Era of Multistage Refracturing in Conventional Reservoirs of Western Siberia

Abstract

Drilling of the horizontal wells in Russia is increasing both regarding the numbers of wells and meterage. Recently, one of the NOC reported 47% increase in a number of horizontal wells. It is clear now that shift towards horizontal wells completed with multi-stage hydraulic fracturing is increasing. On the other hand, an economic lifetime of these wells not always met. For the vertical well, a well-known and successful technique for the well revitalization is re-fracturing. Vertical wells have been responding so positively, that some operators perform refracturing up to four times on the same well. In case of the horizontal well, one of the most significant uncertainties is the fluid entry point. Starting from uneven depletion of the horizontal part of the well, not knowing the fluid entry point may lead to ineffective well re-stimulation and absence of any positive effect. In this paper, we will demonstrate integrated approach towards horizontal well re-stimulation: starting from proper reservoir evaluation and candidate selection to engineered treatment design. Several novel methods and techniques have been used: dynamic diverting agent, that has been developed to fit particularities of the conventional reservoirs, and high-frequency pressure monitoring technique, which has served as an engineering tool for fluid entry point validation.