Comparison of Wormhole Profiles on Carbonate Rocks Using Emulsified and Single-Phase Retarded Acids

Acid retardation through emulsification is commonly used in reservoir stimulation operations, however, emulsified acid are viscous fluids, thus require additional equipment at field for preparation and pumping requirements. Mixture of HCl with organic acids and/or chemical retarders have been used developed to retard acid reaction with carbonate, however, lower dissolving power. Development of low viscosity and high dissolving retarded acid recipes (e.g., equivalent to 15-26 wt.% HCl) addresses the drawbacks of emulsified acids and HCl acid mixtures with weaker organic acids. The objective of this study is to compare wormhole profile generated as a result of injecting acids in Indian limestone cores using 28 wt.% emulsified acid and single-phase retarded acids at comparable dissolving power at 200 and 300°F. Coreflood analysis testing was conducted using Indiana limestone core plugs to assess the pore volume profile of retarded acid at temperatures of 200 and 300° F. This test is supported by Computed Tomography to evaluate the propagation behavior as a result of the fluid/rock reaction. Wider wormholes were observed with 28 wt.% emulsified acid at 200°F when compared to test results conducted at 300°F. The optimum injection rate was 1 cm3/min at 200 and 300°F based on wormhole profile and examined flow rates. Generally, face-dissolution and wider wormholes were observed with emulsified acids, especially at 200°F. Narrower wormholes were formed as a result of injecting retarded acids into Indiana limestone cores compared to 28 wt.% emulsified acid. Breakthrough was not achieved with retarded acid recipe at 300°F and flow rates of 1 and 3 cm3/min, suggesting higher flow rates (e.g., > 3 cm3/min) are required for the retarded acid to be more effective at 300°F.

A Review on Part Geometric Precision Improvement Strategies in Double-Sided Incremental Forming

Low geometric accuracy is one of the main limitations in double-sided incremental forming (DSIF) with a rough surface finish, long forming time, and excessive sheet thinning. The lost contact between the support tool and the sheet is considered the main reason for the geometric error. Researchers presented different solutions for geometric accuracy improvement, such as toolpath compensation, adaptation, material redistribution, and heat-assisted processes. Toolpath compensations strategies improve geometric precision without adding extra tooling to the setup. It relies on formulas, simulation, and algorithm-based studies to enhance the part accuracy. Toolpath adaptation improves the part accuracy by adding additional equipment such as pneumatically or spring-loaded support tools or changing the conventional toolpath sequence such as accumulative-DSIF (ADSIF) and its variants. It also includes forming multi-region parts with various arrangements. Toolpath adaptation mostly requires experimental trial-and-error experiments to adjust parameters to obtain the desired shape with precision. Material redistribution strategies are effective for high-wall-angle parts. It is the less studied area in the geometric precision context in the DSIF. The heat-assisted process mainly concentrates on hard-to-form material. It can align itself to any toolpath compensation or adaptation strategy. This work aims to provide DSIF variants and studies, which focus on improving geometric accuracy using various methodologies. It includes a brief survey of tool force requirements for different strategies, sheet thickness variation in DSIF, and support tool role on deformation and fracture mechanism. Finally, a brief discussion and future work are suggested based on the insights from several articles.

The role of choledochoscopy in transductal laparoscopic common bile duct exploration

Laparoscopic common bile duct exploration (LCBDE) performed by choledochoscope through the cystic duct or directly through the incision in the common bile duct (CBD) are well established methods for restoring biliary drainage function in patients with choledocholithiasis. Although it plays a crucial role in the transcystic approach, transductal approach can be achieved differently. However, it has restrictions in availability due to its expensiveness. Objective — to report efficacy of transductal LCBDE without laparoscopic choledochoscopy. Materials and methods. This is a prospective study of urgently admitted patients who underwent trans‑ductal LCBDE due to confirmed choledocholithiasis. During laparoscopy, clearance of the CBD was achieved in two ways: by choledochoscopy (group CS+, n = 43) and without it (group CS–, n = 34). The data of patient demographics, comorbidities, operative outcomes, morbidity, mortality and long‑term biliary complications were analysed and compared between the groups. Results. Out of a total of 154 patients with confirmed choledocholithiasis, the trans‑ductal approach of LCBDE was applied to 77 patients. In 43 patients, clearance was done with choledochoscope (group CS+) and in 34 patients without it (group CS–). Gallstone related complications and comorbidities did not differ between the groups. Surgery was done 4 days after admission in both groups. Median duration of the operation was significantly shorter in the group CS–, 93 vs 120 minutes (p = 0.036), without any difference in conversion and complication rates. Clearance rate was markedly high in both groups. Conclusions. Transductal laparoscopic common bile duct exploration without choledochoscopy is a time‑saving, safe and effective way for CBD clearance, without additional equipment.

New Method of Materials Flow Calculation for Double-String SLCI Type Cement Plant (Part 2: Suspension Preheater and Calciners)

In many industries, energy auditing is important as the basis for controlling processes and designing additional equipment or modifying an existing plant. However, it requires detailed data of the materials flow, which often cannot be determined easily by direct measurement due to high-temperature limitations. This paper presents the second part of an integrated study to perform energy auditing in a separate line and in-line calciners (SLC-I) type cement plant. The second part of this study, as presented in this paper, focused on the materials flow calculation for eight separate cyclones and two calciners. The least square method was employed for solving the obtained overdetermined system equations. Using the operation data from Part 1 of the study, calculation of the detailed materials flow in each cyclone was executed. The results showed that the separation efficiency of cyclones 1A, 2A, 3A, 4A and 1B, 2B, 3B, 4B was 93.86%, 89.80%, 84.41%, 81.98% and 93.96%, 88.70%, 88.53%, 80.72% respectively and the estimated calcination percentage of kiln feed coming out of the ILC and the SLC was 85.3% and 56.3%, respectively. These values are impossible to be measured directly in the cyclones and calciners during plant operation.

An Alternative Tool for Production Logging in Horizontal Wells

From year to year, well drilling is becoming more technologically advanced and more complex, therefore we observe the active development of drilling technologies, well completion and production intensification. It forms the trend towards the complex well geometry and growth of the length of horizontal sections and therefore an increase of the hydraulic fracturing stages at each well. It's obvious, that oil producing companies frequently don't have proved analytical data on the actual distribution of formation fluid in the inflow profiles for some reasons. Conventional logging methods in horizontal sections require coiled tubing (CT) or downhole tractors, and the well preparation such as drilling the ball seat causing technical difficulties, risks of downhole equipment getting lost or stuck in the well. Sometimes the length of horizontal sections is too long to use conventional logging methods due to their limitations. In this regard, efficient solution of objectives related to the production and development of fields with horizontal wells is complicated due to the shortage of instruments allowing to justify the horizontal well optimal length and the number of MultiFrac stages, difficulties in evaluating the reservoir management system efficiency, etc. A new method of tracer based production profiling technologies are increasingly applied in the global oil industry. This approach benefits through excluding well intervention operations for production logging, allows continuous production profiling operations without the necessity of well shut-in, and without involving additional equipment and personal to be located at wellsite.

15K Multistage Fracturing Completion System Addresses Operational Challenges, Improves Production Performance and Cost Savings in Openhole Environments

Multistage fracturing (MSF) ball drop completion systems have been utilized around the globe for effectively treating formations completed as open hole and cemented. Multiple, high-rate hydraulic fracturing stages are pumped through these completions while gaining efficiency during pumping operations. A challenge within the industry was developing systems that are capable of higher pressures (greater than 10k psi) while still being able to be deployed in challenging openhole environments with minimum equipment and intervention requirements. This paper will discuss the planning, deployment and fracturing execution operations of an improved version of one of these systems. To be able to effectively utilize any MSF completion system; formation properties, deployment environment, lateral length, openhole size, liner size, and tubing movements during fracturing should be thoroughly analyzed and equally considered. To create a reliable system, another important consideration is how the system will be deployed; a long string to surface, or will it be deployed as part of a liner hanger system? In the case of the latter, it should be compatible with the liner hanger system by accommodating multiple balls to set and release the hanger system and actuate the openhole packers. In tight formation environments, where treating pressure differentials reaches as high as 15,000 psi during fracturing operations, openhole packers that are capable of holding these pressures in challenging openhole conditions are needed. Not only the packers but also the remaining completion system components need to be capable of withstanding, including burst, collapse, and ball-to-ball seat differential while simultaneously accommodating the pressure with cooling and ballooning induced tubing movement caused by these high pressure treatments. Improving such a robust design with innovative solutions, such as dissolvable frac balls that can handle 15,000 psi differential, optimizes the overall process. The completion design, deployment, and subsequent fracturing operations on a well showcases how effective consideration of components operates as a system can create a reliable MSF system. It also demonstrates how close collaboration between reservoir management, production engineering, completion experts, and vendor results in a coordination of efforts that eliminates operational hazards, thus ensuring smooth operations. The successful deployment of an openhole MSF completion system that can handle 15,000 psi with dissolving frac balls and eliminating openhole anchors helped pave the way to deal with tighter formations in an efficient and cost-effective manner. With the help of this new technology, the well planners were able to address operational challenges that would have otherwise required additional equipment or would have limited deployment capabilities. The engineering approach and design to develop this completion system and utilization in the right candidate confirmed the benefit of the novel completion for field development options.

Usage of Two-Sided Motors as a Part of the Simultaneous Separate Operation Technology

The technology of simultaneous, separate operation is a mandatory condition within the framework of Russian legislation for the production of oil and gas from multilayer reservoirs, which implies a share of a load of several pumps on different reservoirs. To reduce high additional equipment costs and metal consumption of the well, an assembly of two ESPs with one engine was developed. More than forty Russian wells were supplied with double ESP system motors. The project implementation enabled using separate simultaneous operations with more wells and developing reservoirs more accurately. It became possible to develop each reservoir by employing separated data from gauges connected to two reservoirs. The use of two side motors allows using such complicated technologies as separate simultaneous operations for even small and previously not economically achievable reservoirs. According to well inflow calculations, using the most suitable pump, the correct amount of liquid from each reservoir has been produced during these operations.

A Quality Control Check to Ensure Comparability of Stereophotogrammetric Data between Session and Systems

Optoelectronic stereophotogrammetric (SP) systems are widely used in human movement research for clinical diagnostics, interventional applications, and as a reference system for validating alternative technologies. Regardless of the application, SP systems exhibit different random and systematic errors depending on camera specifications, system setup and laboratory environment, which hinders comparing SP data between sessions and across different systems. While many methods have been proposed to quantify and report the errors of SP systems, they are rarely utilized due to their complexity and need for additional equipment. In response, an easy-to-use quality control (QC) check has been designed that can be completed immediately prior to a data collection. This QC check requires minimal training for the operator and no additional equipment. In addition, a custom graphical user interface ensures automatic processing of the errors in an easy-to-read format for immediate interpretation. On initial deployment in a multicentric study, the check (i) proved to be feasible to perform in a short timeframe with minimal burden to the operator, and (ii) quantified the level of random and systematic errors between sessions and systems, ensuring comparability of data in a variety of protocol setups, including repeated measures, longitudinal studies and multicentric studies.

Mathematical modeling of improving the characteristics of bitumen for asphalt concrete by modifying

A significant increase in traffic intensity and increased axle loads of vehicles on the roads led to the fact that asphalt concrete is not able to provide the required durability of road surfaces. The durability of asphalt concrete pavements is directly related to the quality of the materials used, primarily bitumen. Bitumen is most susceptible to changes under the influence of traffic loads and weather conditions. At the same time, bitumen largely determines the condition of the road surface. The behavior of bitumen can be changed by modifying it with additives. The novelty of bitumen modification lies in the fact that the addition of polymer to bitumen makes it possible to obtain a road surface that is resistant to cracking at low temperatures and to provide fatigue strength at high temperatures. Rutting resistance is also achieved. An important role in the choice of the modifier is played by economic issues related to the rise in the cost of coating, as well as the need to use additional equipment, the stability of the modified binder during storage and transportation, etc. Carbon nanotubes (CNTs) were used as a modifier for asphalt concrete mixtures. During the experiment, a significant improvement in the main indicators of asphalt concrete mixtures was revealed, as well as the maximum permissible deviations for the amount of binder in the asphalt concrete mixture and for the main indicators were observed. Moreover, the most important thing that has been achieved is a significant increase in rutting resistance by rolling a loaded wheel.

Antimicrobial textile modified with silver nanoparticles in-situ synthesized using weed leaves extract

Silver nanoparticles (AgNPs) presence has considerable impact on microbial growth. In this paper, AgNPs was deposited on surface of four textiles to enhance the anti-microbial properties using immersion technique. Immersion technique was selected since it was simple, no need high energies, and no additional equipment required. In addition, AgNPs was synthesized using in situ-bio technique which is non-toxic, harmless and eco-friendly approach. Four textiles were evaluated, such as TA, TB, TC and TD. The finding projected that antifungal ability was correlated to the type of the textiles. TC textile has the significant antimicrobial activity with 12.33 ± 2.08 of inhibition zone which followed by TD (16.00 ± 3.46), TB (17.67 ± 7.09), and TA (17.67 ± 6.65). In addition, the surface bonding AgNPs on textile was possibility caused by the -OH group. It has a lone pair of electrons on the O atom that can interact with AgNPs to form –OAg bonds.