scholarly journals A Laboratory Investigation on the Way to Remove the Filter Cake Generated by Ilmenite Water-Based Drilling Fluids

2021 ◽  
Vol 5 (2) ◽  
pp. 1-14
Author(s):  
Mahmoud O

The increasing demand for deeper drilling and more complicated wells fastens the way for improved drilling fluid (mud) technologies and promising additives. Several studies have shown numerous improvements in mud characteristics upon using ilmenite compared to the commonly used weighting materials. This study aims at investigating the removal of filter cake deposited by ilmenite water-based drilling fluid under harsh conditions using low-concentration (7.5 wt%) of hydrochloric acid (HCl) and chelating agent (HEDTA) to prevent iron precipitation during reaction. API filter press was used to conduct the filtration tests and generate the filter cake at a pressure ~ 300 psi and temperature ~ 250°F. Different sandstone cores of 2.5-in. diameter and 1-in. thickness were used to simulate the formation during filtration. Filtrate fluids were collected for 30 minutes as per API procedures and computerized tomography (CT) scan was used to characterize the cores with the deposited filter cakes. The filter cakes were soaked with HCl–chelate solution for six hours. Cores with the remaining filter cakes were CT scanned again. Effluent solutions resulting from the aforementioned soaking process were analyzed using inductively coupled plasma (ICP). Scanning electron microscopy–energy dispersive spectroscopy (SEM-EDS) was used to analyze the dried filter cakes and remaining residue. CT scan and SEM-EDS showed two layers of the filter cake with different densities but similar elemental composition. Using 7.5 wt% of HCl can partially remove the filter cake generated by ilmenite water-based drilling fluids. Adding the chelate showed minimal impact on the filter cake removal-efficiency; however, it helped nullify the corrosion issues during the treatment. This study provides a step forward on the way to chemically remove ilmenite-based filter cake using low acid concentration and virtually overcome corrosion issues encountered while acidizing.

2013 ◽  
Vol 135 (4) ◽  
Author(s):  
Salaheldin Elkatatny ◽  
Mohamed Mahmoud ◽  
Hisham A. Nasr-El-Din

Previous studies considered the water-based drilling fluid filter cake as homogenous, containing one layer with an average porosity and permeability. The filter cake was recently proved to be heterogeneous, containing two layers with different properties (thickness, porosity and permeability). Heterogeneity of the filter cake plays a key role in the design of chemical treatments needed to remove the filter cake. The objectives of this study are to describe filter cake buildup under static and dynamic conditions, determine change in the filter medium properties, and obtain the local filtration properties for each layer in the filter cake. A high pressure high temperature (HPHT) filter press was used to perform the filtration process at 225 °F and 300 psi. A CT (computed tomography) scanner was used to measure the thickness and porosity of the filter cake. The results obtained from the CT scan showed that under static conditions, the formation of filter cake changed from compression to buildup; while under dynamic conditions, the filter cake was formed under continuous buildup. The CT results explained the changes in the thickness and porosity of each layer of the filter cake with time. The CT scans showed the change in the properties of the ceramic disk, such as porosity and permeability, which affect the calculation of the filter cake permeability. The change of the properties of the filter medium was ignored in previous studies.


Author(s):  
Massara Salam ◽  
Nada S. Al-Zubaidi ◽  
Asawer A. Al-Wasiti

In the process of drilling directional, extended-reach, and horizontal wells, the frictional forces between the drill string and the wellbore or casing can cause severe problems including excessive torque which is one of the most important problems during drilling oil and gas well. Drilling fluid plays an important role by reducing these frictional forces. In this research, an enhancement of lubricating properties of drilling fluids was fundamentally examined by adding Lignite NPs into the water-based drilling fluid. Lubricity, Rheology and filtration properties of water-based drilling fluid were measured at room temperature using OFITE EP and Lubricity Tester, OFITE Model 900 Viscometer, and OFITE Low-Pressure Filter Press, respectively. Lignite NPs were added at different concentrations (0.05 %, 0.1 %, 0.2 %, 0.5 %, and 1 %) by weight into water-based drilling fluid. Lignite NPs showed good reduction in COF of water-based drilling fluid. The enhancement was increased with increasing Lignite NPs concentrations; 23.68%, 35.52%, and 45.3 % reduction in COF were obtained by adding 0.2%, 0.5%, and 1% by weight Lignite NPs concentration, respectively.


2012 ◽  
pp. 1-22
Author(s):  
Issham Ismail ◽  
Rosli Illias ◽  
Amy Shareena Abd. Mubin ◽  
Masseera Machitin

The effective cleanup of filter cakes in long, horizontal open-hole completions can maximize an oil well’s productivity. A cleaning solution was formulated which comprised effective microorganisms and a viscoelastic surfactant in order to degrade filter cakes of water-based mud. Generally, the effectiveness of the microorganisms in degrading filter cakes is influenced by temperature and its concentration. To overcome the problem, the viscoelastic surfactant has been used to extend the application of temperature range and increase the viscosity of the cleaning solution. Laboratory studies were conducted to examine the effectiveness of the microorganisms in degrading filter cakes. The apparent viscosity of cleaning solution was measured as a function of shear rate (102.2 s and 1022 s ) and temperature (25 to 80°C). The surface tension of the cleaning solution was measured at room temperature. Static fluid loss tests were performed using the HPHT Filter Press in order to determine the effectiveness of the cleaning solution in degrading filter cake at different temperatures ranging from 100°F to 300°F. Experimental results showed that the cleaning solution could effectively degrade the filter cake. Soaking process was performed until 48 hours and it showed that at temperature 200°F and below, the pure effective microorganisms achieved the highest efficiency of filter cake degradation, i.e. 34.9%. However, at temperature 300°F, cleaning solution that contained effective microorganisms and higher concentration of viscoelastic surfactant was found to perform better. The viscoelastic surfactant succeeded in increasing the viscosity of the cleaning solution, thus enhanced the rate of degradation of filter cakes, i.e. 33.4% at 300°F. The surface tension of the cleaning solution did not change significantly at various concentrations at room temperature.


1999 ◽  
Vol 121 (3) ◽  
pp. 149-153 ◽  
Author(s):  
U. A. Tare ◽  
N. E. Takach ◽  
S. Z. Miska ◽  
F. B. Growcock ◽  
N. Davis

This work discusses the effect of incorporating blast furnace slag (BFS) as an additive in water-based drilling fluids. The intent of this treatment is rapid development of a thin, impervious, and easily removable filter cake, thereby minimizing detrimental impact of the drilling fluid on formation productivity as opposed to previous applications of BFS in universal fluids. To evaluate the impact of BFS on filter cake properties, permeability plugging apparatus (PPA) tests and dynamic formation damage (DFD) studies were conducted. Drill-in fluids and dispersed muds were tested using varying quantities of BFS. Once a steady rate of dynamic filter cake deposition was achieved, the BFS in the filter cakes was chemically activated. The results obtained from these activation studies were compared with those obtained with no BFS and with unactivated BFS. The nature of the filter cakes was examined with an environmental scanning electron microscope (ESEM). Results obtained from the PPA tests indicate substantial decreases in initial spurt loss and filtrate volume with increasing concentration of BFS. The DFD studies substantiate the aforementioned observations and show enhancement of return permeabilities with BFS activation. ESEM studies demonstrate that BFS can consolidate filter cakes.


2012 ◽  
Vol 27 (02) ◽  
pp. 282-293 ◽  
Author(s):  
Salah Elkatatny ◽  
Mohamed A. Mahmoud ◽  
Hisham A. Nasr-El-Din

2017 ◽  
Vol 140 (5) ◽  
Author(s):  
Jimoh K. Adewole ◽  
Musa O. Najimu

This study investigates the effect of using date seed-based additive on the performance of water-based drilling fluids (WBDFs). Specifically, the effects of date pit (DP) fat content, particle size, and DP loading on the drilling fluids density, rheological properties, filtration properties, and thermal stability were investigated. The results showed that dispersion of particles less than 75 μm DP into the WBDFs enhanced the rheological as well as fluid loss control properties. Optimum fluid loss and filter cake thickness can be achieved by addition of 15–20 wt % DP loading to drilling fluid formulation.


Author(s):  
Petar Mijić ◽  
Nediljka Gaurina-Međimurec ◽  
Borivoje Pašić

About 75% of all formations drilled worldwide are shale formations and 90% of all wellbore instability problems occur in shale formations. This increases the overall cost of drilling. Therefore, drilling through shale formations, which have nanosized pores with nanodarcy permeability still need better solutions since the additives used in the conventional drilling fluids are too large to plug them. One of the solutions to drilling problems can be adjusting drilling fluid properties by adding nanoparticles. Drilling mud with nanoparticles can physically plug nanosized pores in shale formations and thus reduce the shale permeability, which results in reducing the pressure transmission and improving wellbore stability. Furthermore, the drilling fluid with nanoparticles, creates a very thin, low permeability filter cake resulting in the reduction of the filtrate penetration into the shale. This thin filter cake implies high potential for reducing the differential pressure sticking. In addition, borehole problems such as too high drag and torque can be reduced by adding nanoparticles to drilling fluids. This paper presents the results of laboratory examination of the influence of commercially available nanoparticles of SiO2 (dry SiO2 and water-based dispersion of 30 wt% of silica), and TiO2 (water-based dispersion of 40 wt% of titania) in concentrations of 0.5 wt% and 1 wt% on the properties of water-based fluids. Special emphasis is put on the determination of lubricating properties of the water-based drilling fluids. Nanoparticles added to the base mud without any lubricant do not improve its lubricity performance, regardless of their concentrations and type. However, by adding 0.5 wt% SiO2-disp to the base mud with lubricant, its lubricity coefficient is reduced by 4.6%, and by adding 1 wt% TiO2-disp to the base mud with lubricant, its lubricity coefficient is reduced by 14.3%.


2021 ◽  
Vol 11 (1) ◽  
pp. 137-145
Author(s):  
Hani Ali Al Khalaf ◽  
Zeeshan Ahmad ◽  
Gabriella Kovácsné Federer

This study aims to evaluate the effect of wheat flour as a natural and environmentally friendly material on the properties of water-based mud. Recently, many experiments have been conducted with various additives to improve the properties of drilling fluids. The effect of using wheat flour as a new additive to drilling fluid was studied to improve rheological and filtration properties. In the laboratory several samples of water-based mud were prepared, different concentrations of wheat flour from 1 wt% to 7 wt% were added to the mud and tested by using a Fann 35 viscometer, 140 Fann Mud balance, and an API LT-LP filter press. The results showed that adding 7 wt% of wheat flour was the optimal concentration. It was found that the apparent viscosity and yield point increased by 50% and 35%, respectively, when 7 wt% of wheat flour was added to the water-based drilling fluid. Likewise, the fluid loss rate was reduced by 25% when using the same concentration of wheat flour.


Energies ◽  
2021 ◽  
Vol 14 (6) ◽  
pp. 1644
Author(s):  
Camilo Pedrosa ◽  
Arild Saasen ◽  
Bjørnar Lund ◽  
Jan David Ytrehus

The cuttings transport efficiency of various drilling fluids has been studied in several approaches. This is an important aspect, since hole cleaning is often a bottleneck in well construction. The studies so far have targeted the drilling fluid cuttings’ transport capability through experiments, simulations or field data. Observed differences in the efficiency due to changes in the drilling fluid properties and compositions have been reported but not always fully understood. In this study, the cuttings bed, wetted with a single drilling fluid, was evaluated. The experiments were performed with parallel plates in an Anton Paar Physica 301 rheometer. The results showed systematic differences in the internal friction behaviors between tests of beds with oil-based and beds with water-based fluids. The observations indicated that cutting beds wetted with a polymeric water-based fluid released clusters of particles when external forces overcame the bonding forces and the beds started to break up. Similarly, it was observed that an oil-based fluid wetted bed allowed particles to break free as single particles. These findings may explain the observed differences in previous cutting transport studies.


2014 ◽  
Vol 136 (3) ◽  
Author(s):  
Arild Saasen

Controlling the annular frictional pressure losses is important in order to drill safely with overpressure without fracturing the formation. To predict these pressure losses, however, is not straightforward. First of all, the pressure losses depend on the annulus eccentricity. Moving the drillstring to the wall generates a wider flow channel in part of the annulus which reduces the frictional pressure losses significantly. The drillstring motion itself also affects the pressure loss significantly. The drillstring rotation, even for fairly small rotation rates, creates unstable flow and sometimes turbulence in the annulus even without axial flow. Transversal motion of the drillstring creates vortices that destabilize the flow. Consequently, the annular frictional pressure loss is increased even though the drilling fluid becomes thinner because of added shear rate. Naturally, the rheological properties of the drilling fluid play an important role. These rheological properties include more properties than the viscosity as measured by API procedures. It is impossible to use the same frictional pressure loss model for water based and oil based drilling fluids even if their viscosity profile is equal because of the different ways these fluids build viscosity. Water based drilling fluids are normally constructed as a polymer solution while the oil based are combinations of emulsions and dispersions. Furthermore, within both water based and oil based drilling fluids there are functional differences. These differences may be sufficiently large to require different models for two water based drilling fluids built with different types of polymers. In addition to these phenomena washouts and tool joints will create localised pressure losses. These localised pressure losses will again be coupled with the rheological properties of the drilling fluids. In this paper, all the above mentioned phenomena and their consequences for annular pressure losses will be discussed in detail. North Sea field data is used as an example. It is not straightforward to build general annular pressure loss models. This argument is based on flow stability analysis and the consequences of using drilling fluids with different rheological properties. These different rheological properties include shear dependent viscosity, elongational viscosity and other viscoelastic properties.


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