NMR fluid analyzer applying to petroleum industry

Abstract

Tremendous progress of developing nuclear magnetic resonance (NMR) fluid analyzer has been witnessed in the oil industry for last two decades. This device allows extensive and accurate exploration of fluid properties, such as its hydrogen content, composition, viscosity, hydrogen index (HI), mud filtrate invasion, gas to oil ratio, average velocity, velocity distribution etc., in the situations of in situ downhole or surface Petro-pipelines. In this review article, we focus on the design principle, manufacturing, implementation, methodology and applications of NMR fluid analyzer to oil and gas industry. A detailed description of the state-of-art NMR fluid analyzers was firstly given to exhibit their respective characteristics. With these experiences on hand, we introduced a series of NMR fluid analyzers designed by us at China University of Petroleum-Beijing with continuous optimizations, in terms of magnet construction, antenna layout, circuit design and operating surroundings. These systems discussed in this article have been demonstrated to achieve multiple NMR parameter acquisition when the fluid is in stationary or flowing state. In the end, a prototype was fabricated and validated considering a vast of engineering influences, such as variable temperatures in a large range, high pressure, limited volume, detection efficiency, etc. A particular emphasis of this paper is to expedite the measurement efficiency of the NMR fluid analyzer to reduce the operation costs. This dilemma can be Figured out by upgrading both pulse sequence and observational mode. For different fluid states, two rapid pulse sequences were proposed to sufficiently obtain the multi-dimensional NMR correlation map. Meanwhile, two observational modes were developed to take full advantage of the polarization time, during which the individual antenna was systematically switched. Another domain of interest in this review concerns the applications of this new tool. For stationary fluids case, accurate identification of fluid properties is of great value for scheme building in oil and gas exploration process. Particularly, it can acquire the fluid content by different NMR responses of different components. In addition, with Bloembergen theory and Stokes–Einstein equation, not only molecular dynamics and composition, but also oil viscosity can be readily evaluated. Moreover, HI information of crude oils will be speculated through partial least square regression. As for flowing fluids case, velocity is a significant parameter to understand the in situ fluid exploitation and therefore evaluate the productivity of certain oil wells or pipelines. Regarding to the unique magnet and antenna designs in our NMR fluid analyzer; this review adopts two distinct methods to obtain flow velocity at a wide rating scale. The first one is a time-of-flight method adaptive in a homogeneous magnetic field, which is suitable in the case of fluid at high flow velocity. The other one relies on the adjacent echo phase difference at a magnetic field with constant gradient, which is preferred for relatively low flow velocity. In the near future, this tool will be tested underground to offer individual fluid velocities by combining both the stationary and flowing analysis methods.

Cavitation‐Associated Water Evaporation From Porous Media Through In Situ NMR Characterization

“…In particular, to characterize the transient water distribution, nuclear magnetic resonance (NMR) and magnetic resonance imaging (MRI) have become versatile tools. NMR‐MRI allow to study the evaporation processes noninvasively (Guillot et al., 1991; Koptyug et al., 2000; Saidov et al., 2015; Thiery et al., 2017) and thus have been used for a broad range of applications to study various fluid dynamics in subsurface porous media (Ala‐Korpela, 2007; Liao et al., 2021; Liaw et al., 1996; Liu et al., 2018), To date, the experimental evidences have shown interesting and diversified evaporation dynamics from porous media, like the capillary‐assisted air invasion or sometimes the emergence of cavitation.…”

Tandem Mass Spectrometry in the Analysis of Petroleum-Based Compounds

“…Petroleum (or crude oil) is considered one of the most complex mixtures of organic compounds on earth. , Knowledge of the chemical composition of petroleum is important for the optimization of the refining procedures that are used to convert crude oil into various products, such as fuels. , Although many analytical techniques, such as nuclear magnetic resonance (NMR) spectroscopy and gas chromatography coupled with flame ionization detection (FID), have been employed for the characterization of petroleum and compounds derived from petroleum, mass spectrometry is the only analytical technique that can provide molecular-level structural and quantitative information for petroleum and its products. ,, While most of the compounds in these mixtures are saturated hydrocarbons, minor amounts of aromatic and heteroatom-containing compounds also exist. The development of very high-resolution instruments has provided much useful information on the elemental compositions of all these compounds.…”