scholarly journals Effects of Porosity and Permeability on Invasion Depth During Drilling Mud-filtrate Invading into a Reservoir Dynamically

2017 ◽  
Author(s):  
Jianhua Zhang
Keyword(s):  
Drilling Mud ◽  
Invasion Depth ◽  
Porosity And Permeability ◽  
Mud Filtrate

scholarly journals Estimating reservoir permeability with borehole radar

Geophysics ◽  
2020 ◽  
Vol 85 (4) ◽  
pp. H51-H60
Author(s):  
Feng Zhou ◽  
Iraklis Giannakis ◽  
Antonios Giannopoulos ◽  
Klaus Holliger ◽  
Evert Slob
Keyword(s):  
Water Saturation ◽  
Time Lapse ◽  
Drilling Mud ◽  
Invasion Depth ◽  
Initial Water ◽  
Oil Drilling ◽  
Reservoir Evaluation ◽  
Reservoir Permeability ◽  
Borehole Radar ◽  
Porosity And Permeability

In oil drilling, mud filtrate penetrates into porous formations and alters the compositions and properties of the pore fluids. This disturbs the logging signals and brings errors to reservoir evaluation. Drilling and logging engineers therefore deem mud invasion as undesired and attempt to eliminate its adverse effects. However, the mud-contaminated formation carries valuable information, notably with regard to its hydraulic properties. Typically, the invasion depth critically depends on the formation porosity and permeability. Therefore, if adequately characterized, mud invasion effects could be used for reservoir evaluation. To pursue this objective, we have applied borehole radar to measure mud invasion depth considering its high radial spatial resolution compared with conventional logging tools, which then allows us to estimate the reservoir permeability based on the acquired invasion depth. We investigate the feasibility of this strategy numerically through coupled electromagnetic and fluid modeling in an oil-bearing layer drilled using freshwater-based mud. Time-lapse logging is simulated to extract the signals reflected from the invasion front, and a dual-offset downhole antenna mode enables time-to-depth conversion to determine the invasion depth. Based on drilling, coring, and logging data, a quantitative interpretation chart is established, mapping the porosity, permeability, and initial water saturation into the invasion depth. The estimated permeability is in a good agreement with the actual formation permeability. Our results therefore suggest that borehole radar has significant potential to estimate permeability through mud invasion effects.

Numerical Modeling of Mud Invasion Profile Based on the Well Logging with the Shallow Depth of Investigation

2012 ◽  
Vol 524-527 ◽  
pp. 148-151
Author(s):  
Yuan Zhong Zhang ◽  
Xiu Ying Miao
Keyword(s):  
Numerical Modeling ◽  
Dynamic Process ◽  
Water Saturation ◽  
Radial Distance ◽  
Well Logging ◽  
Shallow Depth ◽  
Borehole Wall ◽  
Drilling Mud ◽  
Invasion Depth ◽  
Depth Of Investigation

The drilling mud invasion is a dynamic process varying with time and reveal the permeability or the relatively permeability of the formation saturated with fluid. The mud invasion profile denotes the water saturation change with the radial distance from the borehole wall. The logging with the shallow depth of investigation (DOI), such as density logging, neutron logging and shallow electrical logging, often detects the information of the flushed zone. We chose DOI logging to model the slope invasion profile with the hyperbolic secant function, and the calculated logging reading comparing from the real logging reading to optimize the invasion profile. The results show that the mud invasion profile and the invasion depth are strongly affected by porosity, where the invasion depth reduces with porosity adding.

scholarly journals Experimental Research of Shale Pellet Swelling in Nano-Based Drilling Muds

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6246
Author(s):  
Borivoje Pašić ◽  
Nediljka Gaurina-Međimurec ◽  
Petar Mijić ◽  
Igor Medved
Keyword(s):  
Calcium Carbonate ◽  
Zeta Potential ◽  
Experimental Research ◽  
Petroleum Industry ◽  
Laboratory Research ◽  
Drilling Mud ◽  
Wellbore Instability ◽  
Shale Formation ◽  
Drilling Muds ◽  
Mud Filtrate

The drilling of clay-rich formations, such as shale, is an extremely demanding technical and technological process. Shale consists of mixed clay minerals in different ratios and in contact with water from drilling mud. It tends to swell and cause different wellbore instability problems. Usually, the petroleum industry uses various types of salt and/or polymers as shale hydration inhibitors. The aim of this research was to determine whether nanoparticles can be used as shale swelling inhibitors because due to their small size they can enter the shale nanopores, plug them and stop further penetration of mud filtrate into the shale formation. Swelling of bentonite-calcium carbonate pellets after 2 and 24 h in water and drilling mud (water, bentonite, PAC and NaOH) without nanoparticles and with addition of TiO2 (0.5, 1 and 1.5 wt%) and SiO2 (0.5, 1 and 1.5 wt%) nanoparticles was measured using a linear swell meter. Additionally, granulometric analyses of bentonite as well as the zeta potential of tested muds containing nanoparticles were performed. Based on the laboratory research, it can generally be concluded that the addition of SiO2 and TiO2 nanoparticles in water and base drilling mud reduces the swelling of pellets up to 40.06%.

Estimation of in situ hydrocarbon saturation of porous rocks from borehole measurements of spontaneous potential

Geophysics ◽  
2020 ◽  
Vol 85 (6) ◽  
pp. D199-D217
Author(s):  
Joshua Bautista-Anguiano ◽  
Carlos Torres-Verdín
Keyword(s):  
Drilling Mud ◽  
Porous Rocks ◽  
Spontaneous Potential ◽  
The Matrix ◽  
Resistivity Logs ◽  
Petrophysical Model ◽  
Hydrocarbon Saturation ◽  
The Difference ◽  
Mud Filtrate

It has been previously shown that Nernst’s equation is not reliable for the interpretation of spontaneous potential (SP) measurements acquired in hydrocarbon-bearing rocks. We have examined whether the difference between borehole SP measurements and Nernst-equation predictions could be used to estimate in situ hydrocarbon saturation of porous rocks. For this purpose, a new petrophysical model and a mechanistic finite-difference algorithm for simulating SP borehole measurements in the presence of mud-filtrate invasion are used to establish the limits of detectability of hydrocarbon saturation using only SP logs. We find that the optimal conditions for the detection of hydrocarbon saturation from SP borehole measurements are when (1) capillary forces dominate the process of mud-filtrate invasion, (2) the matrix-pore interface region, known as the electrical double layer, has a relevant impact in the diffusion of counterions, and (3) the electrolyte concentration of drilling mud is greater than that of formation water. We also determine why high values of the endpoint of the water relative permeability favor the detection of hydrocarbon-saturated rocks with the SP log. Using measurements acquired in three key wells within a mature and active hydrocarbon field, three blind tests find that our petrophysical model together with the mechanistic SP simulation algorithm enable the estimation of hydrocarbon saturation from SP borehole measurements without the need for resistivity logs or porosity calculations. The estimation is reliable when the volumetric concentration of shale is negligible, the pore network structure is constant throughout the reservoir, and radial invasion profiles are similar to those observed in the calibration key wells.

scholarly journals ANALYSIS OF THE INFLUENCE OF GEOLOGICAL FACTORS ON THE DEPTH OF THE FILTRATE INVADED ZONEAT THE PRIMARY DISCLOSURE OF GRANULAR RESERVOIRS ACCORDING TO THE WELL-LOGGING DATA

2020 ◽  
pp. 16-21
Author(s):  
O. Karpenko ◽  
B. Sobol ◽  
M. Myrontsov ◽  
I. Karpenko
Keyword(s):  
Oil And Gas ◽  
Well Logging ◽  
Drilling Mud ◽  
Gas Wells ◽  
Reservoir Rocks ◽  
Different Types ◽  
Geological Factors ◽  
Invaded Zone ◽  
Characteristic Features ◽  
Mud Filtrate

Possibilities of using the well-logging data for revealing the factors of the geological nature that influence the formation of invaded zone of a drilling mud filtrate at oil and gas wells drilling are considered. Electrical logging data were used with probes of different sizes and different types for adequate calculation of the relative diameter of the invaded zone. 5 wells from the gas condensate field were selected for analysis. The terrigenous section of the wells is represented by the alternation of argillites, siltstones and sandstones. Rocks reservoirs of granular type; the layers with thicknesses from 3,4 to 18,2 m were selected for analysis. The results of statistical analysis (cluster and factor analyzes) revealed 3 groups of rocks, the characteristic features of which are significantly differentfrom the invaded zone, layer thickness and porosity and gas saturation coefficients. It is established that for terrigenous sections with reservoir rocks of granular type (Serpukhovian) for one field on the example of 5 wells there is a maximum direct correlation between the value of the relative diameter of the invaded zone and the thickness of the layers. The conducted researches allow making prognostic estimations concerning the approximate distributions of diameters of an invaded zone in terrigenous cuts in case of accident-free drilling with observance of technological conditions.

scholarly journals A NEW APPROACH TO CALCULATE MUD INVASION IN RESERVOIRS USING WELL LOGS

2014 ◽  
Vol 32 (2) ◽  
pp. 215 ◽  
Author(s):  
Mariléa Ribeiro ◽  
Abel Carrasquilla
Keyword(s):  
Well Logs ◽  
Formation Damage ◽  
Drilling Mud ◽  
New Approach ◽  
Well Completion ◽  
Porosity And Permeability ◽  
Geophysical Logs ◽  
Mathematical Equations ◽  
Para Determinar ◽  
Geological Formations

ABSTRACT. Muds of different compositions are used in the drilling well process, to support the wall of the borehole along with maintenance of pressure, and toremove rock cuttings generated from the geological formations encountered by the drill bit. The drilling mud invades the formations and modifies the zones surroundingthe borehole, mainly, in terms of the physical properties of the rocks, such as porosity and permeability. The identification of this formation damage is important forreservoir characterization, and the subsequent well completion, as well as for the analysis of economic viability. Many years ago, Schlumberger developed a methodfor determining mud invasion diameter using the Tornado Chart. Today, practitioners in the oil industry use the Tornado Chart to present geophysical logs. Improvingupon Schlumberger’s methodology, Crain used mathematical equations to calculate the mud invasion diameter. In this study, we propose a polynomial mathematicalmethod to determine mud invasion diameter. Our method utilizes the same resistivity well logs, namely dual induction log and dual laterology, though different from thatof Schlumberger or Crain methods. The approach developed in this study considers the characteristics of the invasion process while quickly and accurately showingresults in the form of a log that can be visualized adjacent to other logs measured in the borehole.Keywords: formation damage, drilling mud invasion, resistivity well logs. RESUMO. No processo de perfuração de poços são utilizadas diferentes composições de lama com o propósito de suportar a parede do poço, manter a pressão e, ainda, remover os fragmentos de rocha originados pela broca ao atravessar as formações geológicas. A lama de perfuração invade as formações e modifica as zonas circundantes ao poço, sobretudo, em termos das propriedades físicas das rochas, tais como a porosidade e permeabilidade. A identificação deste tipo de dano à formação é importante, principalmente para a caracterização do reservatório, bem como nas atividades posteriores de conclusão do poço e, ainda, na análise deviabilidade econômica. Neste sentido, há muitos anos, a Schlumberger desenvolveu uma maneira de determinar o diâmetro de invasão da lama usando o GráficoTornado, que é utilizado até hoje na indústria do petróleo, essencialmente usando perfis geofísicos. Mais tarde, com o objetivo de melhorar a determinação do diâmetro de invasão, Crain usou equações matemáticas para calcular esse valor, fazendo correções na metodologia da Schlumberger. Neste trabalho, por outro lado, propõe-se um método matemático polinomial para determinar o diâmetro de invasão, que é diferente das metodologias desenvolvidas pela Schlumberger e por Crain, mas também utilizando os mesmos perfis resistivos de poços, ou seja, os perfis de indução (DIL) e laterolog (DLL) duplos. Desta forma, o procedimento desenvolvido no presentetrabalho mostrou-se rápido e preciso, pois considera melhor as características do processo de invasão, mostrando ainda os resultados sob a forma de um perfil ao lado de outros perfis medidos no poço, resultando, assim, numa visualização mais eficiente.Palavras-chave: dano à formação, invasão da lama de perfuração, perfis resistivos de poços.

Sign in / Sign up

Export Citation Format

Share Document