scholarly journals An Enhanced Crack-Plugging and Pressure-Bearing Oil-Based Drilling Fluid System

2020 ◽  
Vol 7 (4) ◽  
pp. 164-168
Author(s):  
Liming Dong
Keyword(s):  
Drilling Fluid ◽  
Economic Losses ◽  
Drilling Fluids ◽  
Mechanism Analysis ◽  
Prevention Measures ◽  
Filtration Loss ◽  
Before And After ◽  
Leakage Site ◽  
New Type ◽  
Fiber Materials

Compared with water-based drilling fluids (WBDF), oil-based drilling fluids (OBDF) are more prone to borehole leakage loss. Once borehole leakage occurs, it’s difficult to handle the leakage site and it will inevitably cause great economic losses. To cope with the major difficulties in OBDF leakage-proof and crack plugging, this paper conducted experiments on an enhanced crack-plugging and pressure-bearing OBDF system starting from the borehole leakage prevention measures. Then, by selecting and optimizing the materials of leakage-proof agent and crack-plugging agent for OBDF, this study prepared a new-type OBDF drilling leakage-proof agent and a new-type OBDF still crack-plugging agent and discussed their action mechanisms. Laboratory experiment and mechanism analysis results showed that, a well-proportioned combination of different type OBDF leakage-proof and crack-plugging materials such as rigid bridging particles, elastic filling particles, and fiber materials had a synergistic plugging effect and quickly formed a dense crack-plugging and pressure-bearing layer with a stable network structure (the "strong-force chain network" model), which had significantly improved the crack-plugging and pressure-bearing performance of the OBDF, and further optimized the enhanced crack-plugging and pressure-bearing OBDF system; before and after the heated rolling aging, the rheological properties and filtration loss performance of the system were good, and the filtration loss of the sand filter cake of the Permeability Plugging Apparatus (PPA) was only 11.4mL, therefore, the proposed agents exhibited good performance in drilling leakage-proof, crack-plugging, and pressure-bearing, and they were helpful to improve the pressure bearing ability of the earth stratums.

Effect of Nano Carbon Spheres on the Properties of Oil-Based Drilling Fluids under High Temperature Conditions

2021 ◽  
Author(s):  
Hanyi Zhong ◽  
Xiangzheng Kong ◽  
Zhengsong Qiu ◽  
Weian Huang ◽  
Xianbin Zhang ◽  
...  
Keyword(s):  
High Temperature ◽  
Yield Point ◽  
Thermal Aging ◽  
Emulsion Stability ◽  
Drilling Fluid ◽  
Drilling Fluids ◽  
Carbon Spheres ◽  
Filtration Loss ◽  
Before And After ◽  
Nano Carbon

Abstract Owing to superior temperature stability in comparison with water-based drilling fluids, oil or synthetic-based drilling fluids are generally preferred for high temperature and high pressure (HTHP) formations. However, the thermal degradation of emulsifiers and polymeric components under HTHP conditions that results in loss of rheological and filtration control, barite sag or even fluid phase separation also occurs. It is a challenge to sustain these properties stable under such harsh condition. Since nanoparticles have potential to provide better thermal stability, improved filtration loss as well as emulsion stability, the aim of this study is to investigate the effect of nano carbon spheres on the properties of oil-based drilling fluids under high temperature conditions. The nano carbon spheres were synthesized with the hydrothermal reaction of glucose. The influence of nano carbon spheres on the rheological, filtration, emulsion stability, settlement stability, as well as lubricity of a typical mineral oil-based drilling fluid with oil to water ratio of 80:20 was investigated before and after thermal aging at 180 and 200°C, respectively. The structure characterization showed that the uniform hard nano carbon spheres exhibited intermediate wettability. Laboratory performance test indicated that, for the oil-based drilling fluid, the addition of nano carbon spheres improved the rheological properties in terms of yield point and the ratio of yield point to plastic viscosity, which is beneficial for transporting of drilling cuttings. After thermal aging at 200 °C, the filtration loss volume was reduced as high as 70%, and desirable filter cake quality was obtained by incorporation of 1.0 wt% spheres, meanwhile the electrical stability was improved both before and after thermal aging. Furthermore, the fluid formulated with the nano carbon spheres generated better barite sag control. The polarizing microscope observation showed that the nano carbon spheres accumulated at the water-oil interface and formed a steric barrier which probably explained the reason of the above enhanced performance. The green synthetic routes and environmental friendly characteristics of the nano carbon spheres, in combination with the excellent properties suggested that the nano carbon spheres hold potential as multi-functional additives for formulating oil-based drilling fluids for HTHP drilling operations.

scholarly journals Experimental Investigation of the Rheological Behavior of an Oil-Based Drilling Fluid with Rheology Modifier and Oil Wetter Additives

Molecules ◽  
2021 ◽  
Vol 26 (16) ◽  
pp. 4877
Author(s):  
Mobeen Murtaza ◽  
Sulaiman A. Alarifi ◽  
Muhammad Shahzad Kamal ◽  
Sagheer A. Onaizi ◽  
Mohammed Al-Ajmi ◽  
...  
Keyword(s):  
High Temperature ◽  
Zeta Potential ◽  
Hot Rolling ◽  
Emulsion Stability ◽  
Drilling Fluid ◽  
Temperature Tolerance ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Before And After ◽  
Rheology Modifier

Drilling issues such as shale hydration, high-temperature tolerance, torque and drag are often resolved by applying an appropriate drilling fluid formulation. Oil-based drilling fluid (OBDF) formulations are usually composed of emulsifiers, lime, brine, viscosifier, fluid loss controller and weighting agent. These additives sometimes outperform in extended exposure to high pressure high temperature (HPHT) conditions encountered in deep wells, resulting in weighting material segregation, high fluid loss, poor rheology and poor emulsion stability. In this study, two additives, oil wetter and rheology modifier were incorporated into the OBDF and their performance was investigated by conducting rheology, fluid loss, zeta potential and emulsion stability tests before and after hot rolling at 16 h and 32 h. Extending the hot rolling period beyond what is commonly used in this type of experiment is necessary to ensure the fluid’s stability. It was found that HPHT hot rolling affected the properties of drilling fluids by decreasing the rheology parameters and emulsion stability with the increase in the hot rolling time to 32 h. Also, the fluid loss additive’s performance degraded as rolling temperature and time increased. Adding oil wetter and rheology modifier additives resulted in a slight loss of rheological profile after 32 h and maintained flat rheology profile. The emulsion stability was slightly decreased and stayed close to the recommended value (400 V). The fluid loss was controlled by optimizing the concentration of fluid loss additive and oil wetter. The presence of oil wetter improved the carrying capacity of drilling fluids and prevented the barite sag problem. The zeta potential test confirmed that the oil wetter converted the surface of barite from water to oil and improved its dispersion in the oil.

Improving the rheological properties of water-based calcium bentonite drilling fluids using water-soluble polymers in high temperature applications

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
Jinliang Liu ◽  
Fengshan Zhou ◽  
Fengyi Deng ◽  
Hongxing Zhao ◽  
Zhongjin Wei ◽  
...  
Keyword(s):  
High Temperature ◽  
Rheological Properties ◽  
Apparent Viscosity ◽  
Drilling Fluid ◽  
Shear Thickening ◽  
Water Soluble ◽  
Drilling Fluids ◽  
Drilling Depth ◽  
Filtration Loss ◽  
Calcium Bentonite

Abstract Most of bentonite used in modern drilling engineering is physically and chemically modified calcium bentonite. However, with the increase of drilling depth, the bottom hole temperature may reach 180 °C, thus a large amount of calcium bentonite used in the drilling fluid will be unstable. This paper covers three kinds of calcium bentonite with poor rheological properties at high temperature, such as apparent viscosity is greater than 45 mPa·s or less than 10 mPa·s, API filtration loss is greater than 25 mL/30 min, which are diluted type, shear thickening type and low-shear type, these defects will make the rheological properties of drilling fluid worse. The difference is attributed to bentonite mineral composition, such as montmorillonite with good hydration expansion performance. By adding three kinds of heat-resistant water-soluble copolymers Na-HPAN (hydrolyzed polyacrylonitrile sodium), PAS (polycarboxylate salt) and SMP (sulfomethyl phenolic resin), the rheological properties of calcium bentonite drilling fluids can be significantly improved. For example, the addition of 0.1 wt% Na-HPAN and 0.1 wt% PAS increased the apparent viscosity of the XZJ calcium bentonite suspension from 4.5 to 19.5 mPa·s at 180 °C, and the filtration loss also decreased from 20.2 to 17.8 mL.

scholarly journals Laponite: a promising nanomaterial to formulate high-performance water-based drilling fluids

2020 ◽  
Author(s):  
Xian-Bin Huang ◽  
Jin-Sheng Sun ◽  
Yi Huang ◽  
Bang-Chuan Yan ◽  
Xiao-Dong Dong ◽  
...  
Keyword(s):  
High Performance ◽  
Drilling Fluid ◽  
Nitrogen Adsorption ◽  
Drill String ◽  
Wellbore Stability ◽  
Fluid Loss ◽  
Drilling Fluids ◽  
Mechanism Analysis ◽  
Water Based ◽  
Inhibition Performance

Abstract High-performance water-based drilling fluids (HPWBFs) are essential to wellbore stability in shale gas exploration and development. Laponite is a synthetic hectorite clay composed of disk-shaped nanoparticles. This paper analyzed the application potential of laponite in HPWBFs by evaluating its shale inhibition, plugging and lubrication performances. Shale inhibition performance was studied by linear swelling test and shale recovery test. Plugging performance was analyzed by nitrogen adsorption experiment and scanning electron microscope (SEM) observation. Extreme pressure lubricity test was used to evaluate the lubrication property. Experimental results show that laponite has good shale inhibition property, which is better than commonly used shale inhibitors, such as polyamine and KCl. Laponite can effectively plug shale pores. It considerably decreases the surface area and pore volume of shale, and SEM results show that it can reduce the porosity of shale and form a seamless nanofilm. Laponite is beneficial to increase lubricating property of drilling fluid by enhancing the drill pipes/wellbore interface smoothness and isolating the direct contact between wellbore and drill string. Besides, laponite can reduce the fluid loss volume. According to mechanism analysis, the good performance of laponite nanoparticles is mainly attributed to the disk-like nanostructure and the charged surfaces.

scholarly journals Oil-Based Drilling Fluid Plugging Method for Strengthening Wellbore Stability of Shale Gas

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Pengcheng Wu ◽  
Chengxu Zhong ◽  
Zhengtao Li ◽  
Zhen Zhang ◽  
Zhiyuan Wang ◽  
...  
Keyword(s):  
Shale Gas ◽  
Drilling Fluid ◽  
Wellbore Stability ◽  
Drilling Fluids ◽  
Fluid System ◽  
Horizontal Drilling ◽  
Wellbore Instability ◽  
Filtration Loss ◽  
Treatment Agent ◽  
Stability Method

Finding out the reasons for wellbore instability in the Longmaxi Formation and Wufeng Formation and putting forward drilling fluid technical countermeasures to strengthen and stabilize the wellbore are very crucial to horizontal drilling. Based on X-ray diffraction, electron microscope scanning, linear swelling experiment, and hot-rolling dispersion experiment, the physicochemical mechanism of wellbore instability in complex strata was revealed, and thus, the coordinated wellbore stability method can be put forward, which is “strengthening plugging of micropores, inhibiting filtrate invasion, and retarding pressure transmission.” Using a sand bed filtration tester, high-temperature and high-pressure plugging simulation experimental device, and microporous membrane and other experimental devices, the oil-based drilling fluid treatment agent was researched and selected, and a set of an enhanced plugging drilling fluid system suitable for shale gas horizontal well was constructed. Its temperature resistance is 135°C and it has preferable contamination resistibility (10% NaCl, 1% CaCl2, and 8% poor clay). The bearing capacity of a 400 μm fracture is 5 MPa, and the filtration loss of 0.22 μm and 0.45 μm microporous membranes is zero. Compared with previous field drilling fluids, the constructed oil-based drilling fluid system has a greatly improved plugging ability and excellent performance in other aspects.

Bentonite Suspension Filtration and its Electro-Kinetics in the Presence of Additives

2021 ◽  
Vol 58 (2) ◽  
pp. 121-126
Author(s):  
R. M. Farag ◽  
A. M. Salem ◽  
A. A. El-Midany ◽  
S. E. El-Mofty
Keyword(s):  
Zeta Potential ◽  
Rheological Properties ◽  
Electrostatic Interactions ◽  
Drilling Fluid ◽  
Colloidal Suspensions ◽  
Drilling Fluids ◽  
Fluid Filtration ◽  
Filtration Loss ◽  
Suspension Filtration ◽  
The Stability

Abstract Invasion of fluids into porous media during drilling can lead to irreparable damage and reduced well productivity. Hence, minimizing the filtration loss of the drilling fluid into the formation is very important. The stability of colloidal suspensions plays a crucial role in controlling the interfacial forces and consequently on minimizing the filtration. The zeta potential is an indicator of the stability of colloids with respect to their electrostatic interactions. In this study, the rheological properties of bentonite suspensions are investigated with and without additives. The starch and CMC were used as additives to enhance the rheological properties of bentonite. The effects of these additives on the drilling fluid filtration were examined. Zeta-potential, viscosity, gel strength and yield point were measured to characterize the extent to which control of the filtration loss of the drilling fluids can be achieved. The zeta-potential and the amount of filtration loss of water-bentonite suspensions were correlated. Finally, the results showed that the addition of either starch or carboxymethyl cellulose (CMC) enhances the filtration properties of water-bentonite suspensions.

New Approaches for Drilling Highly Depleted Reservoir in Deep Water Wells

2021 ◽  
Author(s):  
Ola Mohamed Balbaa ◽  
Hesham Mohamed ◽  
Sherif Mohamed Elkholy ◽  
Mohamed ElRashidy ◽  
Robert Munger ◽  
...  
Keyword(s):  
Deep Water ◽  
Drilling Fluid ◽  
Drill Pipe ◽  
Cost Effective ◽  
Drill String ◽  
Drilling Fluids ◽  
Prevention Measures ◽  
Enabling Factors ◽  
Design Changes ◽  
The Mediterranean

Abstract While drilling highly depleted gas reservoirs with a very narrow drilling window, Common drilling methods like utilizing loss of circulation pills, wellbore strengthening materials and managed pressure drilling (MPD) are being used in several reservoirs, yet it cannot be successful or cost effective if applied in a traditional manner. Innovative approaches to enable drilling wells in highly depleted reservoir in the Mediterranean deep water were adopted. The approaches incorporated design changes to the well and Bottom hole assembly (BHA), optimized drilling practices, and unconventional use of MPD while drilling and cementing production liner. Well design change in comparison to offset wells to allow drilling the reservoir in one hole section. Several design changes were considered in the BHA and drilling fluids to prevent as well as mitigate losses and differential sticking risks. From the BHA viewpoint, one of the key successful prevention measures was maximizing the standoff to reduce the contact area with the formation, this was achieved through utilizing spiral heavy wall drill pipe (HWDP) instead of drill collars in addition to a modeled placement of stabilizers and roller reamers. While on the drilling fluid side, Calcium carbonate material was added to strengthen wellbore, prevent losses and avoid formation damage. Particle size up to 1000 micron and concentration up to 40ppb was used to strengthen the depleted sands dynamically while drilling. Furthermore, as mitigation to stuck pipe, Jar and accelerator placement was simulated to achieve optimum impulse and impact force while maintaining the Jar above potential sticking zone. Whereas to address the consequence of a stuck pipe event, disconnect subs were placed in BHA to allow for recovering the drill string efficiently. MPD was first introduced in the Mediterranean in 2007 and continued to develop this well-known technique to mitigate various drilling challenges. For this well, MPD was one of the key enabling factors to safely drill, run and cement the production liner. Surface back pressure MPD allowed using the lowest possible mud weight in the hole and maintaining downhole pressure constant in order to manage the narrow drilling window between the formation pressure and fracture pressure (less than 0.4 ppg). MPD was also applied for the first time for running and cementing the production liner to prevent losses and achieve good cement quality which is a key to successful well production.

Preparation of a Novel Nano-Polymer as Plugging and Filtration Loss Agent for Oil-Based Drilling Fluids

2013 ◽  
Vol 807-809 ◽  
pp. 2602-2606 ◽  
Author(s):  
Jian Hua Wang ◽  
Jian Nan Li ◽  
Li Li Yan ◽  
Yi Hui Ji
Keyword(s):  
Shale Gas ◽  
Drilling Fluid ◽  
Wellbore Stability ◽  
Drilling Fluids ◽  
Compact Layer ◽  
Thermo Gravimetric ◽  
The Core ◽  
Filtration Loss ◽  
Filtration Properties ◽  
High Temperature High Pressure

Oil-based drilling fluids and synthetic based drilling fluids are frequently used in shale-gas plays when wellbore stability is necessary. In this paper, a novel nano-polymer, as a plugging agent in oil-based drilling fluid, was prepared and characterized by Fourier transform infrared (FTIR), thermo-gravimetric analyses (TGA) and scanning electron microscopy (SEM). The rheological properties, high temperature-high pressure (HTHP) filtration properties and permeability plugging properties of oil-based drilling fluids were greatly improved by adding the nano-polymer, due to its nanometer size and the compact layer formed on the surface of the core.

Study on Preparation and Evaluation of Micro Zirconia Particles Used in Drilling Fluid

2012 ◽  
Vol 578 ◽  
pp. 175-178
Author(s):  
Xiao Chun Cao ◽  
Yan Yu Li ◽  
Dong Liang Yang ◽  
Kun Ke
Keyword(s):  
Hydrothermal Synthesis ◽  
Rheological Properties ◽  
Particle Image ◽  
Drilling Fluid ◽  
Synthesis Method ◽  
Drilling Fluids ◽  
Micro Particles ◽  
Before And After ◽  
Preparation And Evaluation

This article explains how to prepare zirconia (ZrO2) mico particles and demonstrates how to evaluate the performance of drilling fluids containing ZrO2. Sheet ZrO2micro articles were prepared using hydrothermal synthesis method and were observed using particle image equipment. The performances of drilling fluids before and after various doses of ZrO2added were compared. The result shows that sheet ZrO2micro particles can adjust the rheological properties of drilling fluid.

scholarly journals The Preparation and Performances of Self-Dispersed Nanomicron Emulsified Wax Solid Lubricant Ewax for Drilling Fluids

2014 ◽  
Vol 2014 ◽  
pp. 1-7
Author(s):  
Feng-shan Zhou ◽  
Ting-ting Wang ◽  
Zheng-qiang Xiong ◽  
Wen-yue Guo ◽  
Xi Xiang ◽  
...  
Keyword(s):  
Solid Lubricant ◽  
Drilling Fluid ◽  
Water Soluble ◽  
Drilling Fluids ◽  
Soluble Polymer ◽  
Water Soluble Polymer ◽  
Filtration Loss ◽  
Water Based ◽  
Liquid Products ◽  
Reduced Rate

An oil-in-water nanomicron wax emulsion with oil phase content 45 wt% was prepared by using the emulsifying method of surfactant-in-oil. The optimum prepared condition is 85°C, 20 min, and 5 wt% complex emulsifiers. Then the abovementioned nanomicron emulsifying wax was immersed into a special water-soluble polymer in a certain percentage by the semidry technology. At last, a solidified self-dispersed nanomicron emulsified wax named as Ewax, a kind of solid lubricant for water based drilling fluid, was obtained after dried in the special soluble polymer containing emulsifying wax in low temperature. It is shown that the adhesion coefficient reduced rate(ΔKf)is 73.5% and the extreme pressure (E-P) friction coefficient reduced rate(Δf)is 77.6% when the produced Ewax sample was added to fresh water based drilling fluid at dosage 1.0 wt%. In comparison with other normal similar liquid products, Ewax not only has better performances of lubrication, filtration loss control property, heat resistance, and tolerance to salt and is environmentally friendly, but also can solve the problems of freezing in the winter and poor storage stability of liquid wax emulsion in oilfield applications.

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