Downhole pH Measurement for WBM Contamination Monitoring and Transition Zone Characterization

A comprehensive review on characterization and modeling of thick capillary transition zones in carbonate reservoirs

A method for detecting pressure disturbances in a formation accessible by a borehole while performing an operation includes positioning a tool within the borehole, positioning a first probe of the tool at a first location, positioning a second probe of the tool at a second location remote from the first location to obtain a pressure reading, performing an operation with the first probe, detecting the presence of a first phase fluid within the tool, detecting a pressure disturbance within the formation with the second probe, and identifying a second phase fluid based on the detection of the pressure disturbance. Other methods and systems for detecting pressure disturbances in the formation are further shown and described.

System and method for detecting pressure disturbances in a formation while performing an operation

Acquisition of oil samples from the reservoir prior to oil production is essential in order to design production strategies and production facilities In addition, reservoir compartmentalization and hydrocarbon compositional grading magnify the necessity to map fluid properties vertically and laterally in the reservoir prior to production Downhole fluid analysis (DFA), performed in situ in the oil well, helps optimize this fluid mapping process However, for heavy oil reservoirs drilled with water based muds, fluid mapping has been largely precluded due to the formation of stable water‐in‐oil (w/o) emulsions, which add significant complexity to sample acquisition and which can preclude standard DFA measurements Here, fluorescence measurements are shown to be dependent on oil type but independent of the state of emulsion even at very high water fractions Thus, downhole fluorescence measurements can be used to perform hydrocarbon fluid mapping in the reservoir The sensitivities of fluorescence and optic

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Fluorescence Methods for Downhole Fluid Analysis of Heavy Oil Emulsions

In drilling and well completion operations, drilling fluid is a crucial element as it is employed for the purposes of several functions. The main functions of drilling fluid are to control formation pressure, maintain the wellbore stability, transport the cuttings up to surface to clean the borehole bottom as well as to lubricate and cool the drill bit. Moreover, it is used to minimize the drilling damage to reservoir and suspend cuttings when the pumping is stop, hence it will not falling back down the borehole. The purpose of this study is to formulate new drilling mud formulation modified with nanosilica. Six samples of water based mud (WBM) were prepared using three types of polymers, (Xanthan Gum, Hydro Zan Plus and Hydro Star HT), starch and nanosilica. Basic rheological tests such as density, viscosity and pH were carried out. The density test was carried out using mud balance meanwhile the pH test was using pH meter. The plastic viscosity, yield point and gel strength tests were carried out using viscometer. Besides that, physical observation was also performed for as the stability test. The results concluded that water based mud incorporated with polymer Hydro Zan Plus and nanosilica can be a potential candidate to be commercialized as a smart nanodrilling fluid.

Rheological Study of Nanosilica Based Drilling Fluid

background or methods

http://www.netl.doe.gov/File%20Library/Research/onsite%20research/publications/NETL-TRS-7-2015_Development-of-Fiber-Optic-Sensors-for-Downhole-pH_final_20150723.pdf

Downhole pH Measurement for WBM Contamination Monitoring and Transition Zone Characterization

Citations

A comprehensive review on characterization and modeling of thick capillary transition zones in carbonate reservoirs

System and method for detecting pressure disturbances in a formation while performing an operation

Fluorescence Methods for Downhole Fluid Analysis of Heavy Oil Emulsions

Rheological Study of Nanosilica Based Drilling Fluid

Development of Fiber Optic Sensors for Downhole pH Measurement