The Effect of Lemongrass as Lost Circulation Material (LCM) to the Filtrate and Filter Cake Formation

2013 ◽  
Vol 594-595 ◽  
pp. 68-72 ◽  
Author(s):  
Nurul Aimi Ghazali ◽  
T.A.T. Mohd ◽  
Nur Hashimah Alias ◽  
A. Azizi ◽  
A.A. Harun

Lost circulation is one of the most troublesome encountered in drilling due to uncontrolled flow of mud into the formation that likely to be caused of unsuccessful filter cake. The lost circulation material (LCM) is the additives that added to the drilling fluid to control loss of mud to the formation. In this research, the lemongrass was used as LCM. The objectives of this experiment are to investigate the effect of lemongrass as LCM to the filtrate and filter cake thickness and to determine the effective size of lemongrass as LCM. The experiments were conducted to measure the filtrate and filter cake thickness with different size and different based of drilling fluid. Low Pressure Low Temperature (LPLT) filter press is for water based mud (WBM) and High Pressure High Temperature (HPHT) filter press is for oil based mud (OBM) were used to perform the filtration process under static condition and constant filtration time which is 30 minutes. Both WBM and OBM are prepared four samples with three difference sizes of LCM and native mud. The sizes of lemongrass are 150 microns, 250 microns and 500 microns. After each experiment, the filtrate volume and filter cake thickness were determined to represent. The result shows that lemongrass able to perform a good LCM in both WBM and OBM based on filtrate volume and filter cake thickness. For WBM, the mud with LCM is lower filtrate volume than native mud which is less than 6.0 ml and for OBM, the mud with LCM is lower filtrate volume than native mud which is less than 5.0 ml. Both WBM and OBM show the thickness of filter cake obtained was in the range of 2 to 25 mm. The result also shows that the effective size of LCM is 150 micron due to less filtrate volume and filter cake thickness compare to other size of LCM which is 250 microns and 500 microns. The findings revealed that then lemongrass with the size of 150 microns is the suitable material to be used as LCM to replace conventional LCM.

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.


2020 ◽  
Vol 10 (8) ◽  
pp. 3389-3397 ◽  
Author(s):  
Nayem Ahmed ◽  
Md. Saiful Alam ◽  
M. A. Salam

Abstract Loss of drilling fluid commonly known as mud loss is considered as one of the critical issues during the drilling operation as it can cause severe formation damage. To minimize fluid loss, researchers introduced numerous additives but did not get the expected result. Recently, the use of nanoparticles (NPs) in drilling fluid gives a new hope to control the fluid loss. A basic KCl–Glycol–PHPA polymer-based mud is made, and six different concentrations of 0.1, 0.5, 1.0, 1.5, 2.0, 3.0 wt% iron (III) oxide or Hematite (Fe2O3) NPs are mixed with the basic mud. The experimental observations reveal that fluid loss of basic mud is 5.9 ml after 30 min and prepared nano-based drilling mud results in a less fluid loss at all concentrations. Nanoparticles with a concentration of 0.5 wt% result in a 5.1 ml fluid loss at the API LTLP filter press test. On the other hand, nanoparticles with a concentration of 3.0 wt% enhance the plastic viscosity, yield point, and 10 s gel strength by 15.0, 3.0, and 12.5%, respectively. The optimum concentration of hematite NPs is found to be 0.5 wt% which reduces the API LPLT filtrate volume and filter cake thickness by 13.6 and 40%, respectively, as well as an improvement of plastic viscosity by 10%.


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):  
Zisis Vryzas ◽  
Omar Mahmoud ◽  
Hisham Nasr-El-Din ◽  
Vassilis Zaspalis ◽  
Vassilios C. Kelessidis

A successful drilling operation requires an effective drilling fluid system. Due to the variety of downhole conditions across the globe, the fluid system should be designed to meet complex challenges such as High-Pressure/High-Temperature (HPHT) environments, while promoting better productivity with a minimum interference for completion operations. This study aims to improve the rheological and fluid loss properties of water-bentonite suspensions by using both commercial (C-NP) and custom-made (CM-NP) iron oxide (Fe3O4) nanoparticles (NP) as drilling fluid additives. Superparamagnetic Fe3O4 NP were synthesized by the co-precipitation method. Both types of nanoparticles were characterized by a High Resolution Transmission Electron Microscope (TEM) and X-ray Diffraction (XRD). Base fluid (BF), made of deionized water and bentonite at 7wt%, was prepared according to American Petroleum Institute (API) procedures and nanoparticles were added at 0.5wt%. A Couette-type viscometer was used to analyze the rheological characteristics of these fluids at different shear rates and various temperatures (up to 158°F). The rheological parameters were obtained from analysis of viscometric data using non-linear regression. The API Low-Pressure/Low-Temperature (LPLT) and HPHT fluid filtrate volumes were measured, using a standard API LPLT static filter press (100 psi, 77°F) and an API HPHT filter press (300 psi, 250°F). Observation of the porous matrix morphology of the produced filter cakes was done with Scanning Electron Microscope (SEM). TEM showed that the mean diameter of the CM-NP was 7–8 nm, with measured surface areas between 100–250 m2/g. The C-NP had an average diameter of <50 nm, as per manufacturer specifications. The XRD of the CM-NP revealed peaks corresponding to pure crystallites of magnetite (Fe3O4) with no impurities. Rheological analysis showed very good fitting by the Herschel-Bulkley model with coefficient of determination (R2) greater than 0.99. Rheological properties of all samples were affected by higher temperatures, with increase in yield stress, decrease in flow consistency index (K) and slight increase in flow behavior index (n). Fluid filtration results indicated a decrease in the LPLT fluid loss and an increase in the filter cake thickness compared to the BF upon addition of higher concentrations of C-NP, because of a decrease in filter cake permeability. At HPHT conditions, samples with 0.5wt% C-NP had a smaller fluid loss by 34.3%, compared to 11.9% at LPLT conditions. CM-NP exhibited even higher reduction in the fluid loss at HPHT conditions of 40%. Such drilling fluids can solve difficult drilling problems and aid in achieving the reservoir’s highest potential by eliminating the use of aggressive, potentially damaging chemicals. Exploitation of the synergistic interaction of the utilized components can produce a water-based system with excellent fluid loss characteristics while maintaining optimal rheological properties.


2016 ◽  
Vol 78 (8) ◽  
Author(s):  
Nor Fatihah Abdul Majid ◽  
Issham Ismail ◽  
Mohd Fauzi Hamid

Lost circulation is one of the drilling operational problems. It refers to the total or partial loss of drilling fluid into highly permeable zones or natural or induced fractures. This problem is likely to occur when the hydrostatic head pressure of drilling fluid in the hole exceeds the formation pressure. Today, managing lost circulation remains a significant challenge to oilwell drilling operations because it may contribute to high non-productive time. It is imperative to note that the overbalance pressure situation also can cause the invasion of mud filtrate into production zones which will result in formation damage. To address these problems, an experimental investigation has been done on durian rind as an alternative fluid loss and lost circulation materials in water-based mud. Durian rind was selected as a mud loss control material because it contains close to 20% pectin which may complement the formation of high quality mat-like bridges across openings of the formation. The test involved the use of standard mud testing equipment and a lost circulation test cell. Durian rind powder was prepared by cleaning and cutting the durian rind into small pieces of 1 to 2 cm, and then dried them in an oven at 60°C for 48 hours before grinding into five different sizes from coarse to ultra-fine while Hydro-plug, the commercial lost circulation material was supplied by Scomi Energy. The fluid loss test was conducted using a standard low pressure filter press while the bridging test was carried out at 100 psi of pressure difference and ambient temperature using a lost circulation cell. Fine durian in the water-based mud gave the best fluid loss control compared to coarse durian rind, fine and coarse Hydro-plug. The experimental results also showed that at 15 lb/bbl (42.8 kg/m3) optimum concentration, coarse and intermediate durian rind have outperformed Hydro-plug by showing an excellent control of mud losses in 1 and 2 mm simulated fractures.


SPE Journal ◽  
2021 ◽  
pp. 1-23 ◽  
Author(s):  
Kien Nguyen ◽  
Amin Mehrabian ◽  
Ashok Santra ◽  
Dung Phan

Summary Estimation of near-wellbore fracture widths remains central to designing the particle size distribution (PSD) and composition of lost circulation material (LCM) blends. Although elastic rock models are often used for this purpose, they fall short in capturing the substantial effect of pore fluid pressure on the fracture width. The problem is addressed in this paper by incorporating the poroelastic back stress in width estimation of axial fractures nearby an inclined wellbore. The poroelastic back stress is caused by a nonideal drilling fluid filter cake allowing for fluid pressure communication between the wellbore and pore space of the rock surrounding the wellbore. In this aspect, a proper definition of the filter-cake efficiency is made in terms of the wellbore pressure, far-field pore fluid pressure, and pore fluid pressure of the rock surrounding the wellbore. The value of this parameter is estimated from the standard drilling fluid filtration test results, as well as the formation rock permeability. The filter-cake efficiency is next used to develop the long-time, asymptotic analytical solution for the poroelastic stress of an inclined wellbore. By accounting for the obtained poroelastic back stress, an improved estimation of the wellbore tensile limit that depends on the filter-cake efficiency parameter is developed. For wellbore pressures beyond the wellbore tensile limit, the width of the near-wellbore fractures is estimated. The fracture width estimation is made through an analytical, dislocation-based fracture mechanics solution to the integral equation describing the nonlocal stress equilibrium along the fracture faces. The commonly practiced scheme for geometric design of LCM blends is enhanced by using the presented improvement in estimation of the near-wellbore fracture width. A case study is used to demonstrate the substantial effect of drilling fluid filtration properties and the resulting poroelastic back stress on the wellbore tensile limit, estimated fracture width, and consequently, composition of the recommended LCM blend.


2021 ◽  
Author(s):  
Karl Ronny Klungtvedt ◽  
Mahmoud Khalifeh ◽  
Arild Saasen ◽  
Bjørn Berglind ◽  
Jan Kristian Vasshus

Abstract During drilling of permeable reservoirs, drilling fluid may penetrate the formation and induce damage to the reservoir rock. Specifically, solids present in the drilling fluid may enter the formation and cause subsequent reduction in reservoir permeability in the area near the wellbore. When drilling with a water-based drilling fluid in a reservoir, various polymer-based additives are normally applied to reduce the filtration loss. These additives, such as Xanthan Gum, Poly Anionic Cellulose (PAC) and Starch may help in reducing losses to the formation in presence of small pore-throats and low differential pressures. If the pore throats exceed e.g. 20μm and differential pressures reach 500psi, these additives have little effect on reducing loss of drilling fluid to the formation and thereby little effect in preventing solids from entering the formation. Lost circulation is particularly challenging when losses occur in the reservoir section. This is because LCM treatment may create formation damages. Green et al. (SPE-185889) showed the nature of drilling fluid invasion, clean-up, and retention during reservoir formation drilling. They also showed the lack of direct relation between fluid loss and formation damage. In light of such ideas, a development of new Non-Invasive Fluid (NIF) additives was conducted. These additives were able to handle downhole pressure differences and create a preventative sealing of a permeable formation when applied into a solids-free drilling fluid. Ceramic discs of various permeability and mean pore-throat size were installed into a HTHP pressure cell. Drilling fluid was pumped through the cell and a filter cake was formed across the ceramic disc. A pressure of 500psi was applied and filtration loss was measured over a 30-minute period. Examples are herein presented showing how filter cake materials were applied into the drilling fluid and effectively sealing the permeable surface of the ceramic disc. Also, it will be shown how the filter cake was effectively removed from the discs using a breaker solution. Furthermore, a selection of experiments is presented, showing the possibility to heal lost circulation in permeable reservoirs without the presence of weighing materials, clays or drill-solids in the drilling fluid. A test was also conducted in such a way that the disc was fractured inside the test cell to investigate the impact on fluid loss.


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