Baker Hughes, a Ge Compnay, LLC

Baker Hughes Corporation

Baker Hughes Holdings LLC

Alberto Mezzatesta

Zhiyi Zhang

Baoyan Li

Otto N Fanini

Guodong Jin

Babak Kouchmeshky

Hasan Kesserwan

Julio Roberto Arro

Hao Zhang

Raghu K Chunduru

Yinxi Zhang

Rainer Busch

Methods and apparatus for evaluating an earth formation intersected by a borehole. Methods include using at least one transmitter to generate electromagnetic (EM) waves propagating through the formation; generating measurement signals at at least one receiver responsive to the propagating EM waves; taking a plurality of propagation measurements from the measurement signals representative of the propagating EM waves, where each propagation measurement of the plurality comprises at least one of: i) a relative phase shift between a first wave of the plurality of propagating EM waves and a second wave of the plurality of propagating EM waves; and ii) a relative attenuation between a first wave of the plurality of propagating EM waves and a second wave of the plurality of propagating EM waves; and performing a single inversion which uses the plurality of propagation measurements as input and generates at least one petrophysical parameter as output.

Measuring petrophysical properties of an earth formation by regularized direct inversion of electromagnetic signals

A method for transforming an earth formation and/or production equipment based on correcting nuclear magnetic resonance (NMR) data to account for partially water-saturated rock includes: receiving NMR logging data having echo-trains for an earth formation; inverting the echo-trains to provide transverse relaxation time constant (T) distributions for various components of fluid in the earth formation; substituting a Tdistribution for mobile water of fully water-saturated rock for a Tdistribution for mobile water of partially water-saturated rock based on values of the mobile water Tdistribution of partially water-saturated rock and a total porosity constraint; summing the Tdistribution for mobile water of fully water-saturated rock and a Tdistribution for an immobile water component of the fluid to provide a T, distribution for fully water-saturated rock; and transforming the earth formation and/or the production equipment based on a parameter derived from the Tdistribution for fully water-saturated rock.

Fluid substitution method for T2 distributions of reservoir rocks

Examples of techniques for generating a high-resolution lithology model for subsurface formation evaluation are disclosed. In one example implementation according to aspects of the present disclosure, a computer-implemented method includes determining, by a processing device, a low-resolution lithology volumetric model. The method further includes comparing, by the processing device, the low-resolution lithology volumetric model to a high-resolution imaging log. The method further includes calculating, by the processing device, a dynamic boundary curve for each of a plurality of moving windows. The method further includes generating, by the processing device, the high-resolution lithology model based at least in part on the calculated dynamic boundary curve for each of the plurality of moving windows. The method further includes controlling a drilling operation based at least in part on the high-resolution lithology model.

Generating a high-resolution lithology model for subsurface formation evaluation

Methods and apparatus for evaluating a volume of an earth formation carried out using complex dielectric measurements. Methods include making measurements of complex permittivity at a plurality of frequencies; identifying an optimal frequency by: identifying candidate frequencies having a corresponding measurement with a respective sensitivity to at least one of i) salinity and ii) water-filled porosity, by determining that each respective sensitivity is substantially independent of rock texture; selecting a maximum of the candidate frequencies as the optimal frequency; using a table search method based on a forward model to generate an initial estimate of at least two parameters of the volume; and using the initial estimate as an initial condition for an inversion of other measurements at frequencies other than the optimal frequency to generate a final solution comprising final estimates for formation properties. The at least two parameters may comprise water salinity and water filled porosity.

Real-time inversion of array dielectric downhole measurements with advanced search for initial values to eliminate non-uniqueness

A method for estimating liquid and vapor molar fraction of components, liquid mole fraction, vapor mole fraction, liquid saturation, and vapor saturation of a mixture of hydrocarbons in nano-pores in an earth formation includes: constructing an equation of state (EOS) representing the mixture hydrocarbons in the nano-pores in the earth formation; the EOS having a term accounting for capillary pressure in the nano-pores. The method further includes inputting a composition of the mixture of hydrocarbons, a phase pressure of the hydrocarbons and a pore size distribution of the earth formation into the EOS and solving the EOS and to estimate the liquid and vapor molar fraction of components, liquid mole fraction, vapor mole fraction, liquid saturation, and vapor saturation of the mixture of hydrocarbons in the nano-pores in the earth formation.

Method to estimate the influence of pore-size distribution on phase equilibrium of multi-component hydrocarbon systems in unconventional shale gas and oil reservoirs

High Definition Induction Logging (HDIL) tools provide reliable information about the vertical and radial variations of resistivity structure in isotropic media. Focusing techniques provide quantitative information about resistivity variation and qualitative information about invasion at the well site. Coaxial alignment of transmitter-receiver arrays with the borehole prevents obtaining information about anisotropy in vertical wells, thereby greatly limiting the application of array induction tools in the characterization of reservoirs with finely laminated sand/shale sequences. A multi-component induction tool, 3DEX&trade;, enables the detection of anisotropy in laminated reservoirs. Multi-component data are invert to give an estimate of vertical and horizontal resistivity in a vertical borehole. 3DEX&trade; may encounter difficulties in looking through an invaded zone and detecting the anisotropy in the formations. Joint inversion of HDIL and 3DEX&trade; data enables identification of parameters of the invaded zone as well as of the anisotropic formations.

2-D inversion of multi-component induction logging data to resolve anisotropic resistivity structure

A Neural Net (NN) is trained, validated and used for borehole correction of resistivity logging data. In the training stage, the entire range of possibilities of earth models relevant to borehole compensation is sampled and a suite of tool responses is generated, with and without the borehole and the NN is trained to produce the corresponding borehole-free response. In the validation stage, the input to the NN comprises tool responses that were not used in the training of the NN and validation is based upon comparing the output of the NN to the corresponding borehole-free response. If the agreement is not good, then the NN is retrained with a different sampling of the earth model. The validated NN is then used to correct the borehole measurements. The borehole corrected measurements may be inverted using an additional neural net designed for the purpose.

Generic, accurate, and real time borehole correction for resistivity tools

Resistivity data acquired at two different epochs using different types of tools are jointly inverted. For example, a multiple propagation resistivity (MPR) tool is run first, preferably at several frequencies and several transmitter-receiver spacings. At a later epoch, an induction tool may be run, preferably on a wireline. The joint inversion process identifies bed boundaries based on inflection points in the propagation resistivity and induction logging raw data. An initial guess for an uninvaded earth model is generated using the selected bed boundaries and the apparent raw resistivity values. An inversion run using shallow measurements of propagation resistivity logging data is performed to estimate a resistivity structure representative of the near borehole zone resistivity (invaded zone). The bed boundary positions of the layers are also updated as part of the inversion process. Synthetic data for both the shallow and deep measurements are generated to delineate the invasion zones. If the data match is good for both shallow and deep subarrays, then the model obtained from the shallow data is used as the final model for the inversion. In the event the data match is good for short subarrays and not for long subarrays, a final inversion run is performed by introducing invasion in the earth model. The method may be used for inverting data obtained from wireline, MWD or permanently implanted sensors at two or more epochs.

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Houston, TX, United States of America

Alberto Mezzatesta