scholarly journals Ilmenite Inclusion: A Solution towards Solid Sagging for Hematite-Based Invert Emulsion Mud

Geofluids ◽  
2022 ◽  
Vol 2022 ◽  
pp. 1-9
Author(s):  
Salem Basfar ◽  
Ashraf Ahmed ◽  
Salaheldin Elkatatny
Keyword(s):  
Viscoelastic Properties ◽  
Filter Cake ◽  
Emulsion Stability ◽  
American Petroleum Institute ◽  
Optimum Combination ◽  
Drilling Mud ◽  
Gel Structure ◽  
Well Control ◽  
Invert Emulsion ◽  
Drilling Cost

The sagging tendency of hematite in drilling mud is a common challenge occurring at high-pressure and high-temperature (HP/HT) applications. This work studies the performance of hematite-based invert emulsion mud for HP/HT conditions and provides a solution to prevent the hematite settlement using a combination of ilmenite with hematite. Practical mud formulation was utilized over a range of ilmenite/hematite ratios (0/100, 20/80, 40/60, and 50/50%) to study sagging behaviour. From the sag tests, the optimum combination proportion was determined. Thereafter, the density, emulsion stability, rheological and viscoelastic properties, and filtration conduct for the formulated mud were evaluated. The experiments were conditioned as per the standards of the American Petroleum Institute. The obtained results of sagging experiments indicated that including 50% of ilmenite mitigated the hematite settling and reduced the sag tendency towards the safe range. A slight drop (4%) in mud weight was noticed upon adding the ilmenite, whereas the emulsion stability was enhanced from 551 to 574 volts with the 50% ilmenite content. The rheology and viscoelasticity measurements showed that 50/50% combination improved the yield point (YP) by 50% with a trivial 1 cP increment on plastic viscosity (PV), hence enhancing the YP/PV ratio by 46%. Also, the gelling strength was enhanced resulting in flat rheology and better gel structure. The filtration behaviour of 50% ilmenite mud was improved compared to blank hematite as it resulted in 21, 15, and 17% reduction on the filtrated volume, filter cake weight, and thickness, respectively. This study provides a solution for hematite sagging issue at HP/HT using combined weighting agents, which contributes to enhancing the mud stability and avoiding several well control issues and related operational and technical challenges that eventually will economize the drilling cost and time.

Sagging Prevention for Hematite-Based Invert Emulsion Mud

2021 ◽  
pp. 1-19
Author(s):  
Ashraf Ahmed ◽  
Salem Basfer ◽  
Salaheldin Elkatatny
Keyword(s):  
Laboratory Experiments ◽  
Filter Cake ◽  
Emulsion Stability ◽  
Gel Strength ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
High Pressure High Temperature ◽  
Solids Suspension ◽  
Invert Emulsion ◽  
Drilling Cost

Abstract The solids sagging in high-pressure high-temperature (HP/HT) reservoirs is a common challenge associated with hematite drilling fluids. This study provides a solution to hematite sagging in invert emulsion mud for HP/HT wells which involves the combination of Micromax (Mn3O4) with hematite. The particles of both weighting agents were characterized to address their mineralogical features. A Field formulation of the mud was used over a range of Micromax/hematite ratios (0/100, 20/80, and 30/70%) in laboratory experiments to address the sag performance and determine the optimal combination ratio. Then, density, emulsion stability, rheology, viscoelasticity, and filtration performance for the formulated mud were addressed. The tests were conditioned to 500 psi and 350 °F. The acquired results of sag tests indicated that incorporation of 30% Micromax solved the hematite sagging issue and brought the sag tendency within the recommended safe range. An insignificant reduction in mud density was observed upon the inclusion of Micromax, while the emulsion stability was obviously improved from 551 to 614 volts with the 30% Micromax mixture. The recommended 30/70% combination had almost no effect on plastic viscosity and yield point since they were increased by one unit, but the gel strength was improved resulting in flat rheology and better solids suspension capacity. The filtration behavior of the formulation with 30% Micromax was enhanced compared to pure hematite as it resulted in 10 and 14% reduction of the filtrate volume and filter-cake thickness, respectively. This study contributes to improve and economize the drilling cost and time by formulating a stabilized and distinguished-performance drilling mud using combined weighting agents at HP/HT.

Low ECD High Performance Invert Emulsion Drilling Fluids: Lab Development and Field Deployment

2021 ◽  
Author(s):  
Vikrant Wagle ◽  
Abdullah Yami ◽  
Michael Onoriode ◽  
Jacques Butcher ◽  
Nivika Gupta
Keyword(s):  
High Performance ◽  
Filter Cake ◽  
Drilling Fluid ◽  
Field Performance ◽  
Superior Performance ◽  
Core Material ◽  
Drilling Fluids ◽  
Invert Emulsion ◽  
Field Deployment ◽  
Permeability Studies

Abstract The present paper describes the results of the formulation of an acid-soluble low ECD organoclay-free invert emulsion drilling fluid formulated with acid soluble manganese tetroxide and a specially designed bridging package. The paper also presents a short summary of field applications to date. The novel, non-damaging fluid has superior rheology resulting in lower ECD, excellent suspension properties for effective hole cleaning and barite-sag resistance while also reducing the risk of stuck pipe in high over balance applications. 95pcf high performance invert emulsion fluid (HPIEF) was formulated using an engineered bridging package comprising of acid-soluble bridging agents and an acid-soluble weighting agent viz. manganese tetroxide. The paper describes the filtration and rheological properties of the HPIEF after hot rolling at 300oF. Different tests such as contamination testing, sag-factor analysis, high temperature-high pressure rheology measurements and filter-cake breaking studies at 300oF were performed on the HPIEF. The 95pcf fluid was also subjected to particle plugging experiments to determine the invasion characteristics and the non-damaging nature of the fluids. The 95pcf HPIEF exhibited optimal filtration properties at high overbalance conditions. The low PV values and rheological profile support low ECDs while drilling. The static aging tests performed on the 95pcf HPIEF resulted in a sag factor of less than 0.53, qualifying the inherent stability for expected downhole conditions. The HPIEF demonstrated resilience to contamination testing with negligible change in properties. Filter-cake breaking experiments performed using a specially designed breaker fluid system gave high filter-cake breaking efficiency. Return permeability studies were performed with the HPIEF against synthetic core material, results of which confirmed the non-damaging design of the fluid. The paper thus demonstrates the superior performance of the HPIEF in achieving the desired lab and field performance.

Force modeling to develop a novel method for fabrication of hollow channels inside a gel structure

2019 ◽  
Vol 234 (2) ◽  
pp. 223-231 ◽  
Author(s):  
Ranjit Barua ◽  
Himanshu Giria ◽  
Sudipto Datta ◽  
Amit Roy Chowdhury ◽  
Pallab Datta
Keyword(s):  
Viscoelastic Material ◽  
Biomedical Engineering ◽  
Viscoelastic Properties ◽  
Three Dimensional ◽  
Microfluidic Devices ◽  
Robotic Arm ◽  
Complex Geometries ◽  
Gel Structure ◽  
Force Modeling ◽  
Novel Method

Fabrication of hollow channels with user-defined dimensions and patterns inside viscoelastic, gel-type materials is required for several applications, especially in biomedical engineering domain. These include objectives of obtaining vascularized tissues and enclosed or subsurface microfluidic devices. However, presently there is no suitable manufacturing technology that can create such channels and networks in a gel structure. The advent of three-dimensional bioprinting has opened new possibilities for fabricating structures with complex geometries. However, application of this technique to fabricate internal hollow channels in viscoelastic material has not been yet explored to a great extent. In this article, we present the theoretical modeling/background of a proposed manufacturing paradigm through which hollow channels can be conveniently fabricated inside a gel structure. We propose that a tip connected to a robotic arm can be moved in X-, Y-, and Z-axis as per the desired design. The tip can be moved by a magnet or mechanical force. If the tip is further trailed with porous tube and moved inside the viscoelastic material, corresponding internal channels can be fabricated. To achieve this, however, force modeling to understand the forces that will be required to move the tip inside viscoelastic material should be known and understood. Therefore, in our first attempt, we developed the computational force modeling of the tip movement inside gels with different viscoelastic properties to create the channels.

scholarly journals An Experimental Study on the Performance of Calcium Carbonate Extracted from Eggshells as Weighting Agent in Drilling Fluid

2019 ◽  
Vol 9 (1) ◽  
pp. 3859-3862 ◽  
Author(s):  
R. Iqbal ◽  
M. Zubair ◽  
F. Pirzada ◽  
F. N. Abro ◽  
M. Ali ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Drilling Mud ◽  
Gas Well ◽  
Well Drilling ◽  
Naturally Occurring ◽  
Drilling Operations ◽  
Drilling Cost ◽  
New Methodologies ◽  
The Cost

Drilling mud density is an important factor in drilling operations. The cost of the drilling mud used for oil and gas well drilling can be 10%-15% of the total drilling cost, and the deeper the well, the more the needed drilling mud. This research aims to prepare a mud that provides performance similar to the conventional mud and to lower down the dependency of primitive CaCO3 technology by exploring it from trash/polluted and naturally occurring materials. For that purpose, a mud was prepared by replacing primeval CaCO3 with the CaCO3 derived from eggshells, as eggshells contain CaCO3 in high amounts which range from 70% to 95%. The success of this project will provide an affordable solution and an alternative way to explore new methodologies for obtaining CaCO3. According to the 2017 Report of Pakistan Poultry Association (PPA) 18,000 Million table eggs are consumed per year in Pakistan. The obtained results of this research are quite satisfactory. CaCO3 obtained from eggshells is used in high amounts, 275–410g to achieve density ranges from 9.5 to 11.0 pounds per gallon whereas, pure the needed quantity of pure CaCO3 is 150g to obtain the density of 10.5 pounds per gallon. Apart from this, it is also observed that eggshell based CaCO3 samples are more efficient in rheological properties compared to the market samples of CaCO3 t. The pH of pure CaCO3 sample of 10.5 pounds per gallon density is almost the same with the sample of eggshell CaCO3 of 10.5 pounds per gallon density.

scholarly journals An Adaptable Water-Based Mud System for Multiple Applications While Drilling

2019 ◽  
Vol 2 (2) ◽  
Keyword(s):  
Volcanic Ash ◽  
Salt Water ◽  
Drilling Fluid ◽  
Circulation System ◽  
Drilling Mud ◽  
Subsurface Geology ◽  
Water Based ◽  
Drilling Cost ◽  
Drilling Time ◽  
Fluid Characteristics

Due to significant variations of the subsurface geology from the surface to the top of reservoir and requirement of different fluid characteristics for drilling various hole there is a need to use various mud systems. These may include a simple spud mud for surface hole section, an inhibitive drilling fluid for reactive shale section, a salt water-based mud for salt diapirs and salt formations, and a highly lubricating mud for deviated hole sections with high dogleg severity.To optimize each of these separate and distinct scenarios, there is a need to change the mud system while drilling to overcome the technical challenges associated with these formations and wellbore profiles. The change over from one mud system to another is typically done between casing points while constructing the well to overcome specific drilling challenges associated with next whole section.There is significant time and effort required to clean the mud circulation system adequately before a mud change over in order to avoid any contamination of the new mud system.This is especially true when displacing a waterbased mud by an oil-based mud or an oil-based mud by a water-based mud.If this is not done properly, contamination of the new mud by the old mud could be a source of major problems due to partial or complete loss of functional ability of the new mud system. An adaptable drilling mud system that can easily be transformed from a spud mud system to an inhibitive, or a high lubricating or a salt water mud can provide the industry a versatile fluid system with multiple hole section applications.This removes much of the NPT associated with mud changeover, reduces the mud cost as compared to mixing a totally new mud system and eliminates concerns regarding mud contamination as well as any disposal or recycling cost for the replaced system. This paper describes a volcanic ash-based drilling mud that can be used as a spud mud to drill the surface hole, can easily be converted to an inhibitive mud system to drill reactive shale sections of a borehole, a salt water-based mud to drill the salt sections and also a high lubricating water-based drilling mud to reduce torque and drag problems in deviated and horizontal boreholes. The flexible and easily convertible nature of the base volcanic ash-based drilling mud has potential to reduce total drilling cost significantly as it eliminates a significant portion of non-productive drilling time associated with mud changeover, cleaning of mud circulation system, new mud preparation, incorporation of new mud in the circulation system and displacement of the old mud from the borehole by the new mud, etc.

The Effects of Filter-Cake Buildup and Time-Dependent Properties on the Stability of Inclined Wellbores

SPE Journal ◽  
2011 ◽  
Vol 16 (04) ◽  
pp. 1010-1028 ◽  
Author(s):  
Minh H. Tran ◽  
Younane N. Abousleiman ◽  
Vinh X. Nguyen
Keyword(s):  
Pore Pressure ◽  
Filter Cake ◽  
Wellbore Stability ◽  
Time Dependent ◽  
Transient Effects ◽  
Drilling Mud ◽  
Property Variation ◽  
Lost Circulation ◽  
Wellbore Strengthening ◽  
Formation Pore Pressure

Summary The effects of filter-cake buildup and/or filter-cake-property variation with time on wellbore stability have been plaguing the industry. The increasing use of lost-circulation materials (LCMs) in recent years for wellbore strengthening in weak and/or depleted formations necessitates models that can predict these effects. However, the complexities of effective-stress and pore-pressure evolution around the borehole while drilling, coupled with the transient variation of mud-filtration properties, have delayed such modeling efforts. In this paper, the analytical solutions for the time-dependent effects of mudcake buildup and mudcake properties on the wellbore stresses and formation pore pressure, and thus the safe-drilling-mud-weight window, are derived. The transient effects of mudcake buildup and mudcake buildup coupled with its permeability reduction during filtration on the safe-drilling-mudweight window are illustrated through numerical examples. The results showed that the safe-mudweight windows were greatly affected by the buildup of filter cake and its permeability variation. For example, the analysis for filter-cake buildup with cake permeability of 10–2 md showed that the safe-mudweight window was widened by 0.5 g/cc after 2.5 hours post-excavation when compared to the case of a wellbore without mudcake. On the other hand, a lower mudcake permeability of 10–3 md widened the mudweight window by as much as 1 g/cc. Last but not least, the analyses revealed that even for mudcake permeability as low as 10–3 md, neglecting the permeable nature of the mudcake can result in overestimation of the safe-drilling-mudweight window.

Impact of Viscoelastic Characteristics of Oil Based Muds/Synthetic Based Muds on Cuttings Settling Velocities

2017 ◽  
Author(s):  
M. C. Altindal ◽  
E. Ozbayoglu ◽  
S. Miska ◽  
M. Yu ◽  
N. Takach ◽  
...  
Keyword(s):  
Aging Time ◽  
Viscoelastic Properties ◽  
Settling Velocity ◽  
Drilling Fluid ◽  
Time Dependent ◽  
Drilling Fluids ◽  
Structure Development ◽  
Gel Structure ◽  
Fluid Characterization ◽  
Fluid Characteristics

Inaccurate calculation of settling and slip velocities of cuttings leads to inaccurate determination of cuttings concentration and, hence, borehole pressure, as well as inaccurate lag times. To minimize these problems, an understanding of the relation between drilling fluid characteristics and the cuttings transport process is essential. It is desirable for drilling fluids to form a gel structure to help cuttings transportation and suspension of solids. The gel structure development is proportional to increase in aging time. The increase in aging time yields higher shear stress responses at a constant rate of deformation to the drilling fluid sample. The gel structure development helps keep cuttings in suspension and shows a viscoelastic response to small deformations. Understanding these viscoelastic responses is important in rheological characterization and settling velocity prediction. Thus, viscoelastic drilling fluid characteristics should be investigated in depth to better estimate settling and slip velocities of cuttings and to increase cutting transport efficiency. The main focus of this project is to work on viscoelastic and time-dependent fluid characterization to identify the relation between rheological properties and settling velocities of cuttings. Rheological experiments were conducted using an Anton Paar Physica MCR 301 Rheometer. Three different drilling fluids, Water Based Mud (WBM), Oil Based Mud (OBM) and Synthetic Based Mud (SBM), are used for rheological and settling velocity experiments. Stress Overshoot Tests (SOTs) and Steady-Shear experiments were performed to investigate viscoelastic properties and gel structure of the fluids, and to examine time and temperature dependence of WBM, OBM and SBM. Information obtained from the viscoelastic and time-dependent fluid characterization tests was coupled with settling velocity data using both arbitrary shape of cuttings and spherical particles. A mathematical model that considers viscoelastic properties and time dependency of drilling fluids was developed to estimate settling and slip velocities of the cuttings. Comparisons between the proposed models and existing models based on standard rheological measurements were also done. The results show that the proposed model has good agreement with the experimental data.

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