Downhole Fluid Analysis Integrating Insitu Density and Viscosity Measurements - Field Test from an Oman Sandstone Formation

Khalil, M.; Rumhi, Huda; Randrianavony, Mahaly; Cig, Koksal; Mullins, Oliver C.; Godefroy, S.

doi:10.2118/117164-ms

Cited by 5 publications

(1 citation statement)

References 18 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…ST is conducted with a wireline formation tester which has a dual packer module and a single probe for pressure measurements, pumps, a flow control module for low permeability zones and sample chambers for high permeability zones (Fig.1). The wireline formation tester can have many objectives in the same descent such as pressure measurements, downhole fluid identifications, sampling, and vertical interference tests with real-time measurements (Khalil et al 2008). The dual packer interval seals across the 1-m. length of the wellbore.…”

Section: Stress Testing Tool String and Methodologymentioning

confidence: 99%

Advances in Wireline Conveyed In-situ Reservoir Stress Testing Measurements: Case Studies from the Sultanate of Oman

Cig

Mandhari

Msallati³

et al. 2009

All Days

View full text Add to dashboard Cite

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.

show abstract

Section: Stress Testing Tool String and Methodologymentioning

confidence: 99%

Advances in Wireline Conveyed In-situ Reservoir Stress Testing Measurements: Case Studies from the Sultanate of Oman

Cig

Mandhari

Msallati³

et al. 2009

All Days

View full text Add to dashboard Cite

show abstract

Discussion on Formation Fluid Density Measurements and Their Applications

Godefroy

Zuo

Fujisawa

et al. 2008

SPE Annual Technical Conference and Exhibition

View full text Add to dashboard Cite

Knowledge of formation fluid density is necessary for a variety of applications. It provides information on pressure gradient, zonal compartmentalization, transition zone characterization, thin beds analysis, and other reservoir qualities. It also contributes to estimates of the commercial value of the produced fluid and is a critical parameter used in modeling of the reservoir fluids through the equation of state (EOS) to obtain a better representation of fluid Pressure/Volume/Temperature (PVT) properties. Various techniques exist today for the measurement of formation fluid density. These measurements can be taken either at surface on captured fluid samples or downhole in real time using formation tester tools. The different techniques include laboratory PVT analysis of a fluid sample brought to surface, pressure gradients, downhole optical spectroscopy, and, recently developed, density measurements with the in-situ densimeter, which determines density by measuring the resonance characteristics of a vibrating object immersed in the fluid. Although PVT analyses have excellent accuracy, downhole measurements have an advantage over surface measurements as they provide in-situ measurements under reservoir conditions without depending on the quality of the fluid from the sample bottle and sample transfer. They also allow better reservoir characterization without the need for an extensive sampling program. Pressure gradient surveys have been successfully used for decades to provide density measurements of the formation fluids. Although the measurement depends on the accuracy of both pressure measurement and depth, it provides density unaffected by flowline condition of formation testers and mud filtrate contamination. Downhole flowline sensors, such as spectroscopic sensors and vibrating rods, have the advantage of providing density measurements of the fluid itself rather than relying on other parameters such as depth, but they are sensitive to flowline conditions. Whereas the estimation of density from the spectroscopic method relies on an empirical model that cannot be used in every condition, the vibrating rod in-situ density sensor gives a direct physical measurement and is thus the preferred method of measurement whenever available. Introduction Precise fluid characterization provides vital information for reservoir evaluation, flow assurance, facility design, reservoir management, production strategies and reserves definition. Many applications benefit from a precise knowledge of the formation fluid density. Measurements are performed by various techniques at surface or downhole, where some can be intercorrelated to enhance reservoir characterization. Surface measurements include PVT analysis on the formation fluid samples at the wellsite or in a laboratory. Downhole measurements include pretest pressure surveys, molecular spectroscopy measurements and in-situ flowline measurements with vibrating object densimeters. These results are then used for the fluid gradient determination, thin bed analysis, reserve estimation, fluid modeling, zonal connectivity, compositional gradients, contamination estimation, transition zones, compressibility, etc.

show abstract

Introducing the Vibrating Wire Viscometer for Wireline Formation Testing: In-Situ Viscosity

et al. 2010

View full text Add to dashboard Cite

A vibrating wire (VW) viscometer is introduced for the in-situ measurement of formation fluid viscosity. This is the first time this simple and robust technology has been applied downhole to measure formation fluid viscosity with a wireline formation tester in-situ. Extensive laboratory tests have demonstrated the efficacy of the VW viscometer over a wide range of pressures and temperatures, with tests performed with a large variety of live fluids under flowing or static conditions. Field examples described here were performed in water and oil zones, both in wells drilled with oil-based-mud (OBM) and water-based-mud (WBM). Knowledge of formation fluid characteristics, including viscosity, is important for reservoir characterization. A decision as to the economic viability of a well can depend upon fluid mobility, and, by consequence, its viscosity. Fluid profiling vertically or horizontally provides information on compartments, compositional gradients, thin beds, transition zones, and zonal connectivity. Better understanding of the reservoir using in-situ viscosity measurements can illustrate the origin of compositional gradient, whether it originates from gravity segregation, thermal diffusion, incomplete equilibrium migration, asphaltene precipitation, or biodegradation. The ability to perform in-situ viscosity measurements decreases the need for an extensive sampling campaign and costly and time-consuming pressure/volume/temperature (PVT) analysis. It helps the operator make real-time decisions for perforation zones and side track drilling. In this article we briefly describe the theory of the VW viscometer and its suitability for downhole measurements. Laboratory results obtained with the sensor at different conditions of pressure and temperature and over a wide range of viscosity are presented. Field results are presented that were obtained during sampling and/or downhole fluid analysis stations for various fluid and mud types, summarized in the examples below: –Oil viscosity in OBM: We present a case of advanced focused sampling (for very low contamination levels) and fluid analysis used to characterize the formation fluid and reservoir, in northern Kuwait. Viscosity measurements were obtained with a high accuracy and compared very well with two other sensors (DV-Rod sensors for in-situ density) that could be used for viscosity measurements in this environment.–Oil viscosity in WBM: The presence of immiscible fluids presents an extra challenge for sensors as the wetting phase may impede proper clean-up of sensor surfaces, thereby biasing the measurement. However, the VW viscometer, of extremely small cross-section, is able to quickly shed itself of debris, mud, and filtrate. In a first example, within 1 hour of sampling the viscosity measurements stabilized to that expected for oil in this reservoir. In the second example with more viscous oil, the measured viscosity of the emulsified fluid decreased as its water content decreased, in agreement with expectations.–Water viscosity in WBM: We discuss formation water viscosity measurements using the VW viscometer. Such measurements allow one to understand the relative mobility of the water and hydrocarbon phases as well as to discriminate between formation and filtrate waters. Downhole viscosity measurements are presented for formation water that are in agreement with their theoretical values at similar conditions.

show abstract

Downhole Fluid Analysis Integrating Insitu Density and Viscosity Measurements - Field Test from an Oman Sandstone Formation

Cited by 5 publications

References 18 publications

Advances in Wireline Conveyed In-situ Reservoir Stress Testing Measurements: Case Studies from the Sultanate of Oman

Advances in Wireline Conveyed In-situ Reservoir Stress Testing Measurements: Case Studies from the Sultanate of Oman

Discussion on Formation Fluid Density Measurements and Their Applications

Introducing the Vibrating Wire Viscometer for Wireline Formation Testing: In-Situ Viscosity

Contact Info

Product

Resources

About