Fracturing Perspectives in Deep HPHT Well: Comprehensive Analysis using High-Frequency Pressure Monitoring, Flowback-Rebound and Step-Rate Tests

Abstract

Analysis of production perspectives for very deep wells (below 20,000 ft true vertical depth) is closely related to understanding of the hydraulic fracturing perspectives because at these depths, the overburden stresses and long geological history of the target formations usually result in low permeability. Costs of hydraulic fracturing operations in this type of well is significantly higher than in shallower conditions; however, the risk of nonprofitable outcome is significant. A workflow, including several key methods, is suggested to mitigate the operational and financial risks of potential hydraulic fracturing operations in very deep environments. These techniques employ cost-effective yet technically strong tools for determination of required reservoir parameters and well information, including fracture closure pressure, reservoir pressure, formation transmissibility, and well tubulars integrity. Suggested methods avoid well intervention and associated rig and services costs. The workflow was applied in a very deep and hot well with target intervals below 21,000 ft and helped in estimating the fracturing perspectives in an efficient manner.