scholarly journals Investigation of Non-Linear Rheological Characteristics of Barite-Free Drilling Fluids

Fluids ◽  
2021 ◽  
Vol 6 (9) ◽  
pp. 327
Author(s):  
Ekaterina Leusheva ◽  
Nataliia Brovkina ◽  
Valentin Morenov
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Rheological Parameters ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Fluid Properties ◽  
Hydrolyzed Polyacrylamide ◽  
Drilling Muds

Drilling fluids play an important role in the construction of oil and gas wells. Furthermore, drilling of oil and gas wells at offshore fields is an even more complex task that requires application of specialized drilling muds, which are non-Newtonian and complex fluids. With regard to fluid properties, it is necessary to manage the equivalent circulation density because its high values can lead to fracture in the formation, loss of circulation and wellbore instability. Thus, rheology of the used drilling mud has a significant impact on the equivalent circulation density. The aim of the present research is to develop compositions of drilling muds with a low solids load based on salts of formate acid and improve their rheological parameters for wells with a narrow drilling fluid density range. Partially hydrolyzed polyacrylamide of different molecular weights was proposed as a replacement for hydrolized polyacrylamide. The experiment was conducted on a Fann rotary viscometer. The article presents experimentally obtained data of indicators such as plastic viscosity, yield point, nonlinearity index and consistency coefficient. Experimental data were analyzed by the method of approximation. Analysis is performed in order to determine the most suitable rheological model, which describes the investigated fluids’ flow with the least error.

scholarly journals Dependence of the Equivalent Circulation Density of Formate Drilling Fluids on the Molecular Mass of the Polymer Reagent

Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7639
Author(s):  
Ekaterina Leusheva ◽  
Valentin Morenov ◽  
Tianle Liu
Keyword(s):  
Molecular Weight ◽  
Formic Acid ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Technological Parameters ◽  
Gas Wells ◽  
Flow Rates ◽  
Hydrolyzed Polyacrylamide ◽  
Drilling Muds

Construction of offshore gas wells is characterized by increased requirements for both the technological process in general and the technological parameters of drilling fluids in particular. Parameters and properties of the used drilling muds must meet a large number of requirements. The main one is the preservation of the permeability of the reservoirs, in addition to the environmental and technological concerns. At the same time, pressures in the productive formation at offshore fields are often high; the anomaly coefficient is 1.2 and higher. The use of barite in such conditions can lead to contamination of the formation and a decrease in future well flow rates. In this regard, the development and study of the compositions for weighted drilling muds is necessary and relevant. The paper presents investigations on the development of such a composition based on salts of formic acid (formates) and evaluates the effect of the molecular weight of the polymer reagent (partially hydrolyzed polyacrylamide) on the equivalent circulation density of the drilling fluid. The result of the work is a formate-based high-density drilling mud with no barite added. Application of such a mud will preserve the permeability of the productive formation.

Well Clean-Up Using a Combined Thermochemical/Chelating Agent Fluids

2019 ◽  
Vol 141 (10) ◽  
Author(s):  
Mohamed Mahmoud
Keyword(s):  
High Temperature ◽  
Filter Cake ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Chelating Agent ◽  
Drilling Fluids ◽  
Gas Wells ◽  
Oil And Gas Wells ◽  
Different Types ◽  
Cake Removal

The well clean-up process involves the removal of impermeable filter cake from the formation face. This process is essential to allow the formation fluids to flow from the reservoir to the wellbore. Different types of drilling fluids such as oil- and water-based drilling fluids are used to drill oil and gas wells. These drilling fluids are weighted with different weighting materials such as bentonite, calcium carbonate, and barite. The filter cake that forms on the formation face consists mainly of the drilling fluid weighting materials (around 90%), and the rest is other additives such as polymers or oil in the case of oil-base drilling fluids. The process of filter cake removal is very complicated because it involves more than one stage due to the compatibility issues of the fluids used to remove the filter cake. Different formulations were used to remove different types of filter cake, but the problem with these methods is the removal efficiency or the compatibility. In this paper, a new method was developed to remove different types of filter cakes and to clean-up oil and gas wells after drilling operations. Thermochemical fluids that consist of two inert salts when mixed together will generate very high pressure and high temperature in addition to hot water and hot nitrogen. These fluids are sodium nitrate and ammonium chloride. The filter cake was formed using barite and calcite water- and oil-based drilling fluids at high pressure and high temperature. The removal process started by injecting 500 ml of the two salts and left for different time periods from 6 to 24 h. The results of this study showed that the newly developed method of thermochemical removed the filter cake after 6 h with a removal efficiency of 89 wt% for the barite filter cake in the water-based drilling fluid. The mechanisms of removal using the combined solution of thermochemical fluid and ethylenediamine tetra-acetic acid (EDTA) chelating agent were explained by the generation of a strong pressure pulse that disturbed the filter cake and the generation of the high temperature that enhanced the barite dissolution and polymer degradation. This solution for filter cake removal works for reservoir temperatures greater than 100 °C.

scholarly journals Potential use of basidiomycota Trametes hirsuta MT-17.24 in biodegradation of polyanionic cellulose

2021 ◽  
Vol 11 (3) ◽  
pp. 472-480
Author(s):  
A. V. Zubchenko ◽  
E. Yu. Kozhevnikova ◽  
A. V. Barkov ◽  
Yu. A. Topolyuk ◽  
A. V. Shnyreva ◽  
...  
Keyword(s):  
Enzyme Preparation ◽  
Oil And Gas ◽  
Drilling Fluid ◽  
Schizophyllum Commune ◽  
Cellulase Activity ◽  
Drilling Fluids ◽  
Gas Wells ◽  
Trametes Hirsuta ◽  
Enzyme Preparations ◽  
Oil And Gas Wells

Abstract: Despite their efficiency, existing methods to dispose of drilling fluids used in the construction of oil and gas wells (chemical treatment of spent solutions, thermal method, thickening) are often expensive and unsustainable. Basidiomycota are natural xylotroph destructors that process lignocellulosic substrate – one of the most stable biopolymers in nature. Prospects for using enzyme preparations based on Basidiomycota as biodestructors of organic substances are evident due to the high efficiency and zero-waste production. The aim was to obtain an enzyme preparation based on the Trametes hirsute MT-17.24 Basidiomycota strain and evaluate its ability to biodegrade polyanionic cellulose, used as a viscosifier for drilling fluids in the construction and repair of oil and gas wells. Screening of cellulase activity of the following strains was carried out: Fomitopsis pinicola MT-5.21, Fomes fomentarius MT-4.05, Lactarius necator, Schizophyllum commune MT-33.01, Trametes versicolor It-1, Trametes hirsute MT-17.24, Trametes hirsuta MT-24.24. To obtain the enzyme preparation, the T. hirsuta MT-17.24 strain was selected, which demonstrated the highest coefficient of cellulase activity (10.9). A medium for solid-phase cultivation of this strain was selected. Enzymatic activity of the enzyme preparation was studied on a model drilling fluid. A 10-hour experiment showed that the use of a 1% enzyme preparation leads to a decrease in the plastic viscosity of the drilling fluid from 16 to 8 mPa·s. The research results demonstrate the efficiency of enzyme preparations based on Basidiomycota in the biodestruction of polyanionic cellulose.

scholarly journals Modification of DS-01 Drilling Fluid to Reduce Formation Damage

2020 ◽  
Vol 2 (3) ◽  
Author(s):  
Winarto S. ◽  
Sugiatmo Kasmungin
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Laboratory Research ◽  
Formation Damage ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Initial Flow ◽  
Lost Circulation ◽  
Negative Impacts ◽  
Drilling Muds

<em>In the process of drilling for oil and gas wells the use of appropriate drilling mud can reduce the negative impacts during ongoing drilling and post-drilling operations (production). In general, one of the drilling muds that are often used is conventional mud type with weighting agent barite, but the use of this type of mud often results in skin that is difficult to clean. Therefore in this laboratory research an experiment was carried out using a CaCO3 weigting agent called Mud DS-01. CaCO3 is widely used as a material for Lost Circulation Material so that it is expected that using CaCO3 mud will have little effect on formation damage or at least easily cleaned by acidizing. The aim of this research is to obtain a formula of mud with CaCO3 which at least gives formation damage. Laboratory experiments on this drilling mud using several mud samples adjusted to the property specifications of the mud program. Mud sample consists of 4, namely using super fine, fine, medium, and conventional CaCO3. First measuring mud properties in each sample then testing the filter cake breaker, testing the initial flow rate using 200 ml of distilled water and a 20 micron filter disk inserted in a 500 ml HPHT cell then assembled in a PPA jacket and injecting a pressure of 100 psi. The acidification test was then performed using 15% HCL and then pressured 100 psi for 3 hours to let the acid work to remove the cake attached to the filter disk (acidizing). Laboratory studies are expected which of these samples will minimize the formation damage caused by drilling fluids.</em>

Heat Moisture Modified Rice Flours as Additive in Drilling Fluids

2021 ◽  
Vol 80 (1) ◽  
pp. 62-72
Author(s):  
Bunyami Shafie ◽  
Lee Huei Hong ◽  
Phene Neoh Pei Nee ◽  
Fatin Hana Naning ◽  
Tze Jin Wong ◽  
...  
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Low Cost ◽  
Health Concern ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Fluid Mixture ◽  
Gas Drilling ◽  
Water Based ◽  
Rice Flours

Drilling mud is a dense, viscous fluid mixture used in oil and gas drilling operations to bring rock cuttings to the earth's surface from the boreholes as well as to lubricate and cool the drill bit. Water-based mud is commonly used due to its relatively inexpensive and easy to dispose of. However, several components and additives in the muds become increasingly cautious and restricted. Starch was introduced as a safe and biodegradable additive into the water-based drilling fluid, in line with an environmental health concern. In this study, the suitability of four local rice flours and their heat moistures derivatives to be incorporated in the formulation of water-based drilling fluid was investigated. They were selected due to their natural amylose contents (waxy, low, intermediate, and high). They were also heat moisture treated to increase their amylose contents. Results showed that the addition of the rice flours into water-based mud significantly reduced the density, viscosity, and filtrate volume. However, the gel strength of the mud was increased. The rice flours, either native or heat moisture treated, could serve as additives to provide a variety of low cost and environmentally friendly drilling fluids to be incorporated and fitted into different drilling activity.

scholarly journals Improvement of the Rheological and Filtration Properties of Drilling Mud Using the Syrian Clay

2020 ◽  
Vol 26 (5) ◽  
pp. 211-230
Author(s):  
Adnan Ibrahim Barodi
Keyword(s):  
Xanthan Gum ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Drilling Mud ◽  
Clay Concentration ◽  
Fluid Properties ◽  
Drilling Operations ◽  
Solid Part ◽  
Time Required ◽  
Filtration Properties

Drilling fluid properties and formulation play a fundamental role in drilling operations. The Classical water-based muds prepared from only the Syrian clay and water without any additives((Organic and industrial polymers) are generally poor in performance. Moreover, The high quantity of Syrian clay (120 gr / l) used in preparing drilling fluids. It leads to a decrease in the drilling speed and thus an increase in the time required to complete the drilling of the well. As a result, the total cost of drilling the well increased, as a result of an increase in the concentration of the solid part in the drilling fluid. In this context, our study focuses on the investigation of the improvement in drilling mud   Prepared from the Syrian clay by reducing the clay concentration to (50 gr / L). And compensate for the remaining amount (70 gr / l) of clay by adding (natural and industrial polymers) The rheological properties and filtration are measured at different concentrations of polymers .. In light of the experiments, we determine the polymers' concentrations that gave good results in improving the flow properties and controlling the Filter. It is polymers that have given good results:، HEC، HEC and Xanthan Gum  PAC and HEC، CMCHV، PolyAcryl Amid ، Xanthan Gum .

Experiments on Fluid Placement in a Confined Pipe: Fluid Mechanics Analysis for Plug and Abandonment Applications

2020 ◽  
Author(s):  
Soheil Akbari ◽  
Seyed Mohammad Taghavi
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Heavy Fluid ◽  
Cement Slurry ◽  
Gas Wells ◽  
Inflow Velocity ◽  
Operation Conditions ◽  
Oil And Gas Wells ◽  
Cement Plug

Abstract Plug and abandonment (P&A) of oil and gas wells is an essential process to prevent the oil and gas reservoir fluids migration over time and possibly contaminating other formations and also fresh water resources. In order to plug and abandon a well, a high quality cement plug placement is required. One of the most common methods of cement plug placement is the dump bailing method. In this method, a fixed volume of cement is dumped using a bailer on a mechanical plug in the wellbore. The cement slurry occupies the wellbore and also the annular region outside the dump bailer. In the processes of cement slurry placement, an extensive range of Newtonian or non-Newtonian fluids is used to remove the in-situ fluid (drilling fluid or water) in the wellbore. Based on the large number of parameters such as the density and viscosity differences between the fluids, the geometry type (pipe, annulus, etc.), the operation conditions (velocity, geometry inclination, dumping height), various kinds of placement and mixing flows can occur, and different flow regimes (e.g. inertial, viscous) can develop. In this paper, we experimentally study the placement of a heavy fluid to replace an in-situ light fluid in an inclined closed-end pipe (representative of the dump bailing method). The two fluids are Newtonian and miscible, and they have the same viscosity. We investigate the effects of some of the flow parameters such as the dumping height, the pipe inclination, and the inflow velocity of the heavy fluid on the degree of mixing and the placement quality and efficiency. Our results show that the the most efficient displacement happens with the shortest dumping height and at lower inclination from vertical. Also, a high inflow velocity displaces the light fluid promptly with more mixing in comparison with a low inflow rate. The results can help us to develop strategies for improving the dump bailing method in the P&A of the oil and gas wells.

scholarly journals Rheological evaluation of local clay samples in central region Ghana for oil well drilling fluid formulation

2018 ◽  
Vol 7 (1) ◽  
pp. 100
Author(s):  
Foster Gomado ◽  
Forson Kobina ◽  
Augustus Owusu Boadi ◽  
Yussif Moro Awelisah
Keyword(s):  
Oil And Gas ◽  
Drilling Fluid ◽  
Oil And Gas Industry ◽  
Drilling Fluids ◽  
Local Clay ◽  
Gas Industry ◽  
Local Content ◽  
Oil And Gas Operations ◽  
Drilling Muds ◽  
Local Materials

The superb rheological features of bentonites makes them an excellent candidate in drilling operations. Its capacity of bentonite to swell and extend to a few times its unique volume gives it the gelling and viscosity controlling quality. The execution of clay or specifical bentonite as a great consistency controlling operator in drilling fluids largely depends on the great extent of its rheological conduct. Ghana as of late found oil and it has tossed a test to research to explore the utilization of local materials in the oil and gas operations. A rheological study was conducted on local clay samples from Ajumako, Saltpond and Winneba in the Central district of Ghana as a viscosifier in drilling muds. This will help to improve the local content of Ghana's oil and gas industry. Drilling muds were prepared from the samples in addition to a control mud using imported non-treated bentonite. The local clay samples were subjected rheological test where the flow behavior of the muds was determined by measuring the gel strength, plastic viscosity, and the yield point. The experimental values were compared to the API standards. It was revealed that the local clay had some potential features of bentonite and could be utilized as controlling operators in drilling fluids provided the clays are beneficiated to enhance their rheological properties. This novel tend to improve the local content in oil and gas industry in Ghana through the deployment of the local materials in oil and gas operations in the nation.

Buoyant Miscible Flows in Axially Rotating Pipes: the Effects of Pipe Rotation and Viscosity

2021 ◽  
Author(s):  
Shan Lyu ◽  
Seyed Mohammad Taghavi
Keyword(s):  
Oil And Gas ◽  
Deep Understanding ◽  
Axial Rotation ◽  
Drilling Mud ◽  
Gas Wells ◽  
Two Fluids ◽  
Flow Parameters ◽  
Oil And Gas Wells ◽  
Flow Features ◽  
Primary Cementing

Abstract The primary cementing operations of oil and gas wells involve pumping a sequence of fluids into the well (initially within a circular casing and eventually within an annular region) to displace in-situ drilling mud. The fluids involved can be miscible, and they can also have different density and viscosity ratios. It is believed that a casing rotation can generally improve the displacement process, within both the circular casing and the annulus. However, there have not been a lot of laboratory studies to prove that such rotation is indeed effective for the displacement within the casing. In fact, due to the lack of knowledge, the casing axial rotation may not be still among the top recommendations to enhance the displacement occurring within the casing. This is in spite of the fact such a rotation would be feasible using various types of casing heads and special adaptors. In this work, we conduct simulations to understand the fluid mechanics behind buoyant displacement flows that occur within the casing (pipe). Our focus is to analyze the effects of the axial rotation speed of the pipe, the viscosity of the fluids and the viscosity ratio between the two fluids on the flow behaviours. Other flow parameters are also present: the fluids are miscible, and they have a density difference; the pipe inclination angle is considered to be near-horizontal (i.e. the most challenging case in terms of creating efficient displacements). We investigate important flow features, such as the behaviours of the interface between the fluids, the mixing between the fluids, the fluid front velocities, etc. Our results help develop a deep understanding of how casing rotation can be used to enhance displacement flows in the primary cementing operations of oil and gas wells.

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