| Popis: |
Abstract In-situ reservoir stress measurements are essential input to a wide variety of the production and injection applications of reservoirs. Most of the reservoirs in this article require water injection to maximize recovery without breaking the matrices unintentionally. In some cases, it is also important to create a controlled fracture growth in a formation unit without breaking bordering barriers or zones. The main purpose of the in-situ reservoir stress testing of the case studies in this article is to calculate the minimum stress to improve the reservoir management plans for well placement, production, injection and fracturing processes. One approach of measuring stresses in many zones is to use the wireline conveyed stress testing tools. The wireline conveyed in-situ reservoir stress testing measurements are frequently performed in the Sultanate of Oman for a wide range of operational and geomechanics applications such as but not limited to:Hydraulic fracturingFracture growth/containment issuesPolymer injectionBorehole stabilitySand production predictionStress evolution with depletion, hot and cold injection The stress testing zones vary from tight to high permeable zones as well as shale zones. The complexity and wide variety of the stress testing applications inevitably led modifications and improvements on the wireline conveyed stress testing tools. These improvements mainly are various types of pumps, higher performance dual packers and mandrels, innovative stress testing methods. The latest improvements and methods in stress testing help addressing the broader range of formations (deep and shallow, tight and permeable) in an extensive type of wells from vertical or deviated to horizontal. In this article, the examples of several unique stress testing applications are presented. Shale stress testing with a viscous fluid, horizontal well stress testing, tight and very high permeability formation stress testing, sleeve fracturing stress testing methods are discussed in details. Introduction In-situ stress magnitude and direction measurements in vertical and lateral directions are required in a reservoir for several reasons. These are for hydraulic fracture design, fracture type identification, water and gas injection management, fault activity, wellbore stability, sand production, rock mechanical properties, casing strings design, cap and base rock integrity, subsidence, and gas storage design. |
