The MicroPilot* is a log-inject-log technique providing a single-well in-situ measurement of enhanced oil recovery flood geometry and changed residual oil saturation. The fluid to be injected is transported downhole in a sample chamber and injected into the formation through a pencil sized hole. Borehole electric images and high resolution saturation logs are recorded before and after fluid injection. The logs show the change of residual oil saturation. The dimensions of the swept zone and surrounding oil bank are visible on the borehole image. These dimensions and saturations can be used to history match the reservoir simulation of the EOR process.

Many Enhanced Oil Recovery (EOR) applications involve injection of fluids into oil reservoirs to displace and recover as much of the remaining oil as possible. Typical maturation of (chemical) EOR involves phase and compatibility testing in the laboratory, displacement experiments in cores before single or multi-well pilot trials in the field, leading eventually to full field implementation. Recently, a new technique referred to as MicroPilot* has been introduced as an intermediate step to take laboratory results into the field, providing valuable data for pilot design and implementation.The MicroPilot* is a log-inject-log method executed under in-situ conditions downhole in a matter of hours. A suite of wireline openhole logs are utilized to determine the initial saturations. The test then continues with a formation tester string which can drill into open hole, cleanup and inject an EOR agent into the formation. Following injection, the suite of open hole logs are run again to evaluate the effectiveness of the flood by measuring the change in oil saturation and the dimensions of the flood.The world's first successful test has been run in a medium heavy-oil field in the Sultanate of Oman with Alkaline Surfactant Polymer (ASP) solution as the EOR agent. Post-injection formation image logs clearly show the swept zone and an oil bank.In this paper we take the analysis of the test a step further and present dynamic simulation modeling results using the acquired data as benchmark parameters for the history match. Grid verification using single-phase pressure transient analysis is discussed. Each phase of the test is modeled and history-matched to the acquired data. The electrical borehole image log response is matched together with the vertical saturation profile seen on the post injection NMR log. During the history match, formation parameters are fine tuned and some parameters describing the EOR displacement process in the simulator are studied in more detail. The history matching effort not only provided a consistency check for the field observed data but can also help determine a few key modeling parameters prior to possible field pilot planning.

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The MicroPilot* is a log-inject-log technique providing a single-well in-situ measurement of enhanced oil recovery flood geometry and changed residual oil saturation. The fluid to be injected is transported downhole in a sample chamber and injected into the formation through a pencil sized hole. Borehole electric images and high resolution saturation logs are recorded before and after fluid injection. The logs show the change of residual oil saturation. The dimensions of the swept zone and surrounding oil bank are visible on the borehole image. These dimensions and saturations can be used to history match the reservoir simulation of the EOR process.

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 fracturing • Fracture growth/containment issues • Polymer injection • Borehole stability • Sand production prediction • Stress evolution with depletion, hot and cold injectionThe 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.