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# Petrophysics - Science topic

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Questions related to Petrophysics

Hello,

I recently started my PhD trying to apply machine learning in reservoir petrophysical properties prediction. I am a computer science major trying to connect with Petrophysics. However, I am having a challenge knowing the current problem being faced in the industry that be my main research. From the investigation I have done so far, all the problem i could think of have already been solved. I am trying to find a current challenge or problem that is being faced in the oil and gas industry in reservoir petrophysical properties evaluation.

In the oil and gas industry, for technical, economic, and similar reasons, well-Log running is done from special intervals.
Therefore, to build comprehensive models for field development, we will need more information at different depths.
Today, with advances in numerical methods, especially machine learning and deep learning methods, we can use their help to eliminate these data gaps.
Of course, there are methods such as rock physics that are very practical.
But according to my results, part of which is described below. It is better to combine the rock physics method with the deep learning methods, in which case the results will be amazing.
I selected wells from the Poseidon Basin in Australia for testing and got good results.
In this study, by combining the rock physics method and deep learning (CNN + GRU), the values of density, porosity, and shear wave slowness were predicted. A comprehensive database of PEF, RHOB, LLD, GR, CGR, NPHI, DTC, DTS, and water saturation logs was prepared and used as training data for the wells.
The below figure is the result of a blind well test for Torosa well in the Poseidon Basin, Australia.
As you can see, the prediction results are very close to the measured values of shear wave slowness in this well.

- To estimate suitable petrophysical properties, would it will be useful to use CNN or GRU algorithms alone?
- Or, will this estimate will be appropriate when the two methods are combined?
- Convolutional_Neural_Network: In deep learning, a CNN is a class of artificial neural networks, most commonly applied to analyze visual imagery. They are also known as shift invariant or space invariant artificial neural networks (SIANN), based on the shared-weight architecture of the convolution kernels or filters that slide along input features and provide translation equivariant responses known as feature maps. Counter-intuitively, most CNN's are only equivariant, as opposed to invariant, to interpretation.
- Gated_Recurrent_Units: GRU is a gating mechanism in recurrent neural networks, introduced in 2014 by Kyunghyun Cho et al. The GRU is like a long short-term memory with a forget gate, but has fewer parameters than LSTM, as it lacks an output gate. GRUs have been shown to exhibit better performance on certain smaller and less frequent datasets.

Petrophysical and seismic data analysis is one of the key technics for reservoir characterization and pore fluids identification. Rock physics is a link between these data and rock properties, such as porosity, lithology, and pore fluids. Quantitative interpretation and risk assessments of data and uncertainties associated with predictions need methods and multidisciplinary tools that use statistical technics and pattern recognition approaches, in addition to deterministic rock physics relations. The statistical rock physics approach is a way for quantifying the uncertainties in different steps of reservoir exploration and management. This approach applies some of the progressive statistical methods such as the Bayesian approach, Monte Carlo simulation, and Information Entropy. In addition to quantifying the associated uncertainties with predictions and evaluations, the statistical rock physics approach is a useful method to identify the most valuable information for predicting the desired properties.

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**I'm currently focusing on research, which covers topics such as geomechanics, geophysics, statistics, & numerical modeling techniques.**

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**One of my challenges in this research is a gap in log well information in some formation intervals.**

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**Given the time constraints, how can these data gaps be filled with the least amount of uncertainty?**

For a matter of SWT, i need to generate a Density log from the Sonic log that i had. How can i do it ?

Dear All,

I am currently looking for different international examples (papers) of soviet-type/Russian-type geophysical well-log interpretation and application.

This type of archival, geophysical devices were widely used mainly in Europe and Asia in the 1960s-90s. The main difficulty is the proper standarization of this quite specyfic kind of measurements.

I have already found some examples from Poland, but I would like to apply my research to a broader, international perspective. I cannot find any examples from any different area even though I know that these measurements have been used in many countries around the world.

I would really appreciate your help.

How petrophysics can complement magnetic data discussing of structural geology, mineralisation, geology lithology

Hi,

I hope someone can help me. In some wells I have DTSM_Fast, DTSM_Slow, and DTSM. But in some wells, I have only DTSM_Fast and DTSM_slow - no DTSM. Is it possible to calculate DTSM from Fast and Slow? I thought it should be a standard output from advanced shear anisotropy processing (DTSM, DTSM_Fast, DTSM_slow, Stoneley etc.) but some logs, like DTSM, are missing. So now I'm just confused.

I know it isn't just a simple average of DTSM_fast and DTSM_slow because the result doesn't match the DTSM log.

Can you advise, please?

Please recommend materials that may help. Plausible explanations are also highly appreciated.

Thanks

How to simulate the weathering progression of the stone monument ?!, taking into account the presence of different parameters: different lithology, localization of stone, side exposition, insolation, petrophysical and petrographical properties?

and in the same monument.

what is the best approach, in this case, a multivariate study or a bivariate study

Hi,

I am working on the petrophysical modeling of the sandstone reservoir suing Petrel. I have selected three facies i-e sandstone, shaly sandstone and shale on the basis of basic log analysis which is used to prepare facies model. 3D model of the estimated petrophysical propertes i-e porosity, permeavility, water saturation etc have been also prepared.

How I may incorporate the effect of facies (Facies Screening) in my prepared petrophysical model?

What really is meant by facies screening in 3D models?

How I may understand this concept in a clearer way? I have tried to read manuals but unable to execute the process in petrel.

Thanks a lot for your time.

Regards,

As the title, where can I find a relation describing the compressibility and permeability of sedimentary rocks? I am trying to use it as a first guess of initial condition in numerical modeling of sedimentary formations (many layers).

Thank you.

We are looking for a cheaper alternative/addition to Petrel Schlumberger.

We have several Petrel licences, but our capacities have grown lately so we are looking for something new.

Software should be compatible with Petrel, and we aim to use it for well correlation, quantitative seismic, seismic interpretation, geological modeling...

We would be grateful if anyone shared experience on this matter!

I'm trying to search if there are correlations/formulations to determine PSD from OH PP interpretation. Which later can be calibrated to actual PSD from core data.

Appreciate your advice.

Hydrogeology

Hydrology

Petrophysics

Well logging

Hi Everybody, I am seeking guidance to make different realisations (property distribution) in an already developed petrel model. The purpose is to observe the effect of differently distributed properties e.g., porosity, permeability (heterogeneity) on fluid flow. Let’s say, make 10 different realisation and plot their results after simulating in E100 or E300.

Thanks

I am a research student just confused about the workflow for my project.

Please, tell me your opinion.

Who are the world top scientific experts/groups in advanced seismic interpretation techniques in terms of the subsurface characterization? I am talking about people that are defining the state of the art and who are working on the cutting edge of this technology.

Hello

How to make crude oil by combining different materials, such as gasoline?

Also, can i determine API gravity (American Petroleum Institute) for this Crude oil?

Importance of these in the Petrophysical Interpretation.

I am trying to discuss the result of the realizations generated from the volumetric estimation of hydrocarbon in place and I determined the mean and standard deviations of the three cases for each reservoir studied. I need assistance of the what the mean and standard deviations will imply geological to make a good discussion.

Actually I'm working in my dessertation , so I need some help in order to interpret my logging.

if mudstone overlaps with sand, and the porosities that favour production overlap the vertical boundaries, in this case the reservoir will be the sand, and will also include the mudstone, assuming it has moveable hydrocarbons? if yes, what does this mean for the GRV and Net-To-Gross (NTG)?

1.What exactly sand fraction means?Is it 1-Volume(shale)?

I am doing Petrophysical analyasis of a well in Farsi Block (offshore) located in the Iranian water of persian gulf with in western salt basin.

General lithology of the reservoir is Limestone and Dolomite.

There is no core data available.

I couldn't find any other petrophysical study in the same area.

I am struggling to decide Water Saturation equation that can be used in this area.

Any lead would appreciated.

which are th processes that, apart of hydrate dissociation and formation influence the chlorinity profiles in natural gas hydrate systems?

1. Fluid advectio from below? (Which fluids?)

2. Sea level fluctuations? (which is the impact)

...

Is there any available and easy model ?

What are the impacts of gas distribution (continuous vs patchy) and data acquisition (i.e. well log vs seismic)?

i'm going to extract some fractal parameters from a petrophysical signal (well-log) using wavelet transform, i'll be glad if you help me to how choose the suitable mother wavelet for this purpose

I am working on a reservoir simulation project and I am wondering why do we need to provide the data for the capillary pressure to the simulator?

I really need to scale down the rate of injection from field units to laboratory units.

Thanks.

I have petrophysical properties of a core included I.O.I% which is about 10% and I wanna use the results to model a geochemical mechanism.

methods or papers are well accepted :)

I'm interested in particular on fracture filling hydrates

- Measuring porosity from the core Samples.

- Estimating porosity form the satellite image analyses.

- Estimating porosity form the field studies by measuring the fractures dimensions.

i need to construct an equation to calculate the heat flow from the lithology by the aid of will logging

Esteemed Colleagues,

Does anyone have suggestions about couplants for ultrasonic transduers at high PT? Apart from using Au or Pt foil, are there any polymers (?) or other high viscosity materials that will not breakdown at high temperatures? Most of the products I have come across breakdown above 200 degC.

Also, and this is for the vintage generation like me: what was the chemical formula for the couplant V9 made by Dow Corning? It gave beautiful shear signals!

Mahalo,

Manika

Hi,

I have issues applying boundary conditions to my wellbore model. In order to apply principal stress I created a 3d model. Shall I use solid mechanics or Shell for my study, My wellbore shows high strain even at low pressure. Please take a look at model attached, any advice would be appreciated.

I am currently looking for some papers concerning Euler connectivity with specific application to Digital Rock Physics. (I am not looking for papers explaining the basics of this topic, but specifically for applications of this!)

Does anyone have some good suggestions? Especially looking for sandstone related topics. Thanks in advance!

I do need some more information on a sandstone called "Idaho Gray" (link where it was bought attached), especially related to geological setting, formation, depository. If available, also concerning petrophysical investigations.

Thanks for any tipps & hints!

I would like to compare the mean values of petrophysical properties for the same stratigraphic interval at different borehole locations. These properties are determined using empirical regression equations and are assumed to be valid and applicable. Usually, if the preconditions are met, I would apply, e.g., an independent t-test to compare the means of both groups. However, by doing so I am not able to consider the uncertainty in the determination of the single group values (resulting from the application of the regression equation that should allow prediction of the target properties with a mean error ranging between 5 to 15 %). I want to avoid having a false positive result in the comparing-mean test (that means, seeing a significant difference between both means although this results from the uncertainty of the prediction equation and not from real significant variations between both groups). How can I circumnavigate this problem? Does anyone have an idea? Raw data and all statistical parameter of the applied regression equations are available to me. Big thanks in advance.

Dataset for different well logs records in unconventional reservoirs.

I need help to identify the breakthrough of injected water having different salinity than the formation water.

I want to carry out this research, but I have the limitation of data sets. I can get logs and the seismic data, but not the cores/petrographic data. Can anyone suggest what methodology to adopt with this data limitation?