The influence of viscosity characteristics of the drilling mud filtrate on the formation of the reservoir bottom zone

2021 ◽  
pp. 33-37
Author(s):  
A.M. Shishov ◽  
◽  
N.M. Ulyasheva ◽  
Keyword(s):  
Drilling Mud ◽  
Bottom Zone ◽  
Mud Filtrate

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 The Effect of Coconut Fibres, Banana Trunk Peel and Baggasse on the Lost Circulation of the Drilling Mud

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Rizki Akbar ◽  
Abdul Hamid ◽  
Ratnayu Sitaresmi
Keyword(s):  
Filter Press ◽  
Drilling Mud ◽  
Laboratory Equipment ◽  
Lost Circulation ◽  
Banana Tree ◽  
Coconut Fibre ◽  
Stop Loss ◽  
Lost Circulation Materials ◽  
Study Laboratory ◽  
Mud Filtrate

<p>Lost Circulation Materials (LCM) are specially designed not to damage the penetrating formation during handling of loss circulation problems and are very effective for drilling operations worldwide. Optimization of LCM composition may stop loss circulation effectively and protect the production zone from the invasion of mud filtrate. The concentration of lost circulation  materials (LCM) is a key parameter to determine the effectiveness of LCM. In this study, laboratory equipment such as the Hamilton beech mixer, Fann VG meter and API filter press are used to evaluate the effectiveness of various LCMs in dealing with loss circulation. In this research, coconut fibre, banana tree skin, and bagasse are used as LCM in various concentrations. The mud losses were simulated using an 80 mesh shaker. The quality of the muddy rheological properties was<br />the basic parameters to be evaluated. The test was carried out at 80oF and 200oF. The experimental results show that bagasse has the best performance both at 80oF and 200oF as LCM compared withcoconut fibres and banana trunk. The lost circulation of  mud filtrate at 80oF and 200oF due to the addition of 2 gram bagasse is 34 ml and 40 ml, respectively.</p>

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