scholarly journals Development of Hybrid Drilling Fluid and Enzyme–Acid Precursor-Based Clean-Up Fluid for Wells Drilled with Calcium Carbonate-Based Drilling Fluids

ACS Omega ◽  
2020 ◽  
Vol 5 (40) ◽  
pp. 25984-25992
Author(s):  
Bisweswar Ghosh ◽  
Ismail Mohammad AlCheikh ◽  
Debayan Ghosh ◽  
Samuel Ossisanya ◽  
Muhammad Arif
2020 ◽  
Vol 12 (8) ◽  
pp. 3427
Author(s):  
Osama Siddig ◽  
Saad Al-Afnan ◽  
Salaheldin Elkatatny ◽  
Mohamed Bahgat

An impermeable layer “filter cake” usually forms during the overbalanced drilling technique. Even though it helps in protecting the formation from a further invasion of drilling fluids, the removal of this layer is essential for a proper cement job and to avoid any reduction in wellbore deliverability. The design of the removal process is complicated and depends on the filter cake composition and homogeneity. This paper presents an experimental evaluation on the usage of a novel cake washer (NCW) in the removal of a filter cake formed by an invert emulsion oil-based drilling fluid that contains calcium carbonate as a weighting material while drilling a horizontal reservoir. The proposed NCW is a mixture of organic acid, mutual solvent and nonionic surfactant. It is designed to enable restored wellbore permeability for a sustainable production. Since the filter cake mainly consists of the weighting material, the solubility of calcium carbonate in NCW at different ranges of temperature, duration and concentration was investigated. An actual casing joint was used to test the corrosion possibility of the treating solution. High-pressure and high-temperature (HPHT) filtration tests on ceramic discs and Berea sandstone core samples were conducted to measure the efficiency of the filter cake removal and the retained permeability. Ethylene glycol mono butyl ether (EGMBE) was used as a mutual solvent and the solubility was higher compared to when the mutual solvent was not used in the washer formulation. A significant increase in calcium carbonate dissolution with time was observed for a duration of 24 h. The solubility was found to be proportional to the concentration of NCW with optimum results of 99% removal at a temperature of around 212 °F. At those conditions, no major corrosion problems were detected. Permeability of the core retained its pristine value after the treatment.


2021 ◽  
Author(s):  
Abdullah Abdulaziz Alomair ◽  
Hugo Fernando Cuellar ◽  
Mohamed Kashwaa ◽  
Sunil Sharma

Abstract Horizontal sections drilled in conditions that require high mud densities to prevent wellbore collapse are very challenging from both drilling engineering and drilling fluid management point of views. Due to drilling complications, nonaqueous fluids (NAFs) are the best suitable drilling fluids of choice for drilling complex and long horizontal sections. From the other side, as nonacid soluble weighting materials cannot be used while drilling some reservoir sections, which are completed with open screens in open hole, using calcium carbonate is the most economical and best preferred acid soluble/nondamaging option to formulate these fluids. When the density requirements reach above 90 lb/ft3 (12 lb/gal) while using calcium carbonate in the NAFs, fluid formulations exhibit high rheological values due to excessive solids. High solids loading and improper fluids engineering in these high-density ranges lead to hole instability and differential sticking issues in addition to extreme difficulties in managing completions screens runs. These challenges can severely limit the well depth or increase the operation time, impacting profitability of whole project; failing to tackle even one of them could result in catastrophic failure. To overcome above associated challenges, a flexible novel flat rheology invert emulsion system formulation was introduced, which was customized for sustaining high solids loading while maintaining its signature flat-rheology profile. This system uses new technology emulsifier and rheology modifier package for achieving flat-rheology independent of temperature and pressure changes. The fluid formulation was implemented in the area by loading the mud system with more than 330 pounds per barrel of calcium carbonate for reaching densities up to 99 lb/ft3 (13.25 lb/gal). This paper will present a comprehensive overview of novel technology, the steps taken from planning to execution, the overall performance-based results, the cost effectiveness of the new solution, and the challenges during implementation. The troubleshooting steps taken are also discussed for all the challenges that occurred while drilling.


2010 ◽  
Vol 146-147 ◽  
pp. 1075-1079
Author(s):  
Zhi Yong Li ◽  
Jie Nian Yan ◽  
Guang Cheng Jiang ◽  
Shui Xiang Xie ◽  
Ying Jun Fu ◽  
...  

There are continuous high concerns on formation protection technology in international petroleum engineering field. The reservoir drill-in fluid (RDF) is the first non-native fluid to contact formation, and which influences directly the ultimate capacity of oil and gas well. The paper discusses the smart RDF design method based on conventional drilling fluid. The designed RDF system is characterized as good formation damage control, as well as the performance easily adjusted for field application. The technology combines ideal packing technology with active calcium carbonate to obtain low permeability filter cake, high return permeability and low initial flowing pressure. The sized calcium carbonates contribute to develop sealing zone for preventing filtrate and solids from invading into formation, and the organophilic passageway in filter cake (the active calcium carbonate) is favorable to open automatically passageway for oil and gas during production. Different modifiers used to ground calciumcarbonate surface modification are evaluated in laboratory. And the laboratory results show modified calcium carbonates are comfortable with conventional drilling fluids additives such as XC(Xanthan ), potassium polyacrylate(K-PAM), sodium carboxymethyl cellulose(Na-CMC).


2019 ◽  
Vol 17 (1) ◽  
pp. 1435-1441
Author(s):  
Yonggui Liu ◽  
Yang Zhang ◽  
Jing Yan ◽  
Tao Song ◽  
Yongjun Xu

AbstractTraditional water-in-oil drilling fluids are limited by their shear thinning behavior. In this article, we propose the synthesis of a thermal resistant quaternary ammonium salt gemini surfactant DQGE-I. This surfactant was synthesized using monomers such as N,N-dimethyl-1,3-propanediamine, organic acids and epichlorohydrin, as well as blocking groups such as N-vinylpyrrolidone (NVP). The prepared surfactant exhibited various advantages over traditional surfactants, including excellent thermal stability, good emulsifying and wetting capability. The use of these surfactants was shown to improve the compactness of emulsifier molecules at the oil/water interface, as well as the overall emulsificaiton effect. Laboratory studies revealed that water-in-oil emulsions prepared using DQGE-I showed high emulsion breaking voltage, low liquid precipitation and small and uniformly distributed emulsion drops. Highly thixotropic water-in-oil drilling fluids based on DQGE-I showed low viscosity, high shear rate and thermal tolerance up to 260oC. Additionally, the proposed fluid was applied in 16 wells (including WS1-H2, GS3 and XS1-H8) in the Daqing Oilfield. Testing showed that DQGE-1 exhibited excellent rheological behavior and wall-building capability. The emulsion breaking voltage exceeded 1500 V, and the yield point/ plastic viscosity ratio exceeded 0.4. The use of this surfactant can help to solve problems such as high formation temperature and poor well wall stability.


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.


1969 ◽  
Vol 9 (04) ◽  
pp. 403-411 ◽  
Author(s):  
B.K. Sinha ◽  
Harvey T. Kennedy

Abstract Recommendations are made for obtaining consistent and reproducible test data on drilling fluids having identical composition. Previously, such a procedure has been difficult to accomplish even when the fluids were mixed in similar equipment. A survey of work in this area indicates that previous methods have been unsatisfactory because previous methods have been unsatisfactory because (1) the muds are extremely sensitive to the duration and violence of agitation during a normal mixing routine, and (2) gelling of the muds occurs before the properties can reach constant values. This gelling is caused by water evaporation resulting from the increase in temperature associated with the agitation. The work shows that these problems largely can be overcome by (1) agitating the constituents of the drilling fluid more vigorously, (2) maintaining a fairly constant temperature, and(3) Protecting the fluid from evaporation. When these steps are followed, the fluid properties approach asymptotic values that do not change by prolonged or accelerated agitation or by aging for a month. The time required to reach asymptotic values or a stabilized state is from 2 to 6 hours and is a function of the mud composition. Introduction Preparation of drilling fluids in the laboratory to determine their suitability to meet specific drilling requirements or to serve as a base fluid to evaluate the effectiveness of thinners, dispersants or other additives normally begins with combining measured quantities of the constituents and stirring them for a short time in a low-speed mixer. This is done to obtain a uniform mixture and to hydrate clays. Then the fluid is further agitated in a higher-speed device (Hamilton Beach mixer or Waring blender) to disperse more thoroughly and clay particles The biggest obstacle in the laboratory investigation of drilling fluids has been the lack of a method of producing a mixture by which reproducible results of the measured properties could be obtained. Numerous investigators have encountered this difficulty. Prior to 1929, density was the only property of mud that customarily was measured. The use of Wyoming bentonite on a large scale after 1929 was mainly responsible for the development of more elaborate testing procedures and for the application of the principles of colloid chemistry to the drilling fluids. Ambrose and Loomis in 1931 were among the first to recognize the plastic flow characteristics of drilling fluids, although Bingham in 1916 had observed The same phenomenon with dilute clay suspensions. Marsh introduced the Marsh funnel for field testing in 1931. By this time, non-Newtonian characteristics of drilling fluids were established. The Stormer and MacMichael viscometers were used to study the rheological properties of the fluids. In the 1930's and early 1940's, the work conducted by several investigators contributed toward a better understanding of drilling fluids. In the mid 1930's, fluid-loss and the associated mud-cake-forming properties of drilling fluids were recognized as important to the behavior of these fluids. The other properties of drilling fluids, including gel strength, pH, and sand content soon were recognized. In 1937, API published its first recommended procedure for test methods. Since that time, these procedures have been revised periodically. The latest edition, RP-13B, was published in 1961 However, in spite of the recognized need for a method of mixing that provides drilling fluids with stabilized properties, no such method previously has been described. SPEJ P. 403


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.


2021 ◽  
Author(s):  
Vikrant Wagle ◽  
Abdullah Yami ◽  
Michael Onoriode ◽  
Jacques Butcher ◽  
Nivika Gupta

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.


2021 ◽  
Author(s):  
Chen Hongbo ◽  
Okesanya Temi ◽  
Kuru Ergun ◽  
Heath Garett ◽  
Hadley Dylan

Abstract Recent studies highlight the significant role of drilling fluid elasticity in particle suspension and hole cleaning during drilling operations. Traditional methods to quantify fluid elasticity require the use of advanced rheometers not suitable for field application. The main objectives of the study were to develop a generalized model for determining viscoelasticity of a drilling fluid using standard field-testing equipment, investigate the factors influencing drilling fluid viscoelasticity in the field, and provide an understanding of the viscoelasticity concept. Over 80 fluid formulations used in this study included field samples of oil-based drilling fluids as well as laboratory samples formulated with bentonite and other polymers such as partially-hydrolyzed polyacrylamide, synthesized xanthan gum, and polyacrylic acid. Detailed rheological characterizations of these fluids used a funnel viscometer and a rotational viscometer. Elastic properties of the drilling fluids (quantified in terms of the energy required to cause an irreversible deformation in the fluid's structure) were obtained from oscillatory tests conducted using a cone-and-plate type rheometer. Using an empirical approach, a non-iterative model for quantifying elasticity correlated test results from a funnel viscometer and a rotational viscometer. The generalized model was able to predict the elasticity of drilling fluids with a mean absolute error of 5.75%. In addition, the model offers practical versatility by requiring only standard drilling fluid testing equipment to predict viscoelasticity. Experimental results showed that non-aqueous fluid (NAF) viscoelasticity is inversely proportional to the oil-water ratio and the presence of clay greatly debilitates the elasticity of the samples while enhancing their viscosity. The work efforts present a model for estimating drilling fluid elasticity using standard drilling fluid field-testing equipment. Furthermore, a revised approach helps to describe the viscoelastic property of a fluid that involves quantifying the amount of energy required to irreversibly deform a unit volume of viscoelastic fluid. The methodology, combined with the explanation of the viscoelasticity concept, provides a practical tool for optimizing drilling operations based on the viscoelasticity of drilling fluids.


Author(s):  
E.A. Flik ◽  
◽  
Y.E. Kolodyazhnaya

The article assesses the environmental safety of drilling fluids that are currently widely used in the oil and gas industry. It shows active development of water-based drilling fluid systems using xanthan biopolymer.


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