An Integrated Experimental Method to Investigate Tool-Less Temporary-Plugging Multistage Acid Fracturing of Horizontal Well by Using Self-Degradable Diverters

SPE Journal ◽  
2020 ◽  
Vol 25 (03) ◽  
pp. 1204-1219 ◽  
Author(s):  
Lufeng Zhang ◽  
Fujian Zhou ◽  
Jianye Mou ◽  
Wei Feng ◽  
Zhun Li ◽  
...  
Keyword(s):  
Fracture Surface ◽  
Evaluation System ◽  
Horizontal Well ◽  
Single Type ◽  
Fracture Width ◽  
Acid Fracturing ◽  
Integrated Method ◽  
Tight Carbonate ◽  
Operation Cost ◽  
Insight Into

Summary Tool-less temporary-plugging multistage acid fracturing of horizontal well is a necessary technology to unlock the production potential and enable commercial productivity for tight carbonate reservoirs. However, this technique has not been investigated experimentally yet, and the plugging behavior of diverters within acid-etched fracture is still unclear. In this paper, we propose an integrated method to experimentally study tool-less multistage fracturing with diverters. First, we introduce an innovative 3D printing method to reproduce the roughness of acid-etched fracture surface and design an acid-etched fracture temporary plugging evaluation system to satisfy the requirements of temporary plugging experiments. Then, we conduct a series of plugging experiments to optimize the diverter's formula for creating a tight plugging zone within an acid-etched fracture under different fracture widths. On the basis of the description of the fracture surface, we further analyze the formation process and mechanism of temporary plugging. Finally, we further verify through laboratory experiments using a modified true tri-axial fracturing system the feasibility of using a single type of diverter and combined diverters to achieve tool-less temporary plugging staged fracturing of horizontal well. The experimental results show the following findings: (1) Pure fibers can realize temporary plugging at lower fracture width (≤2 mm). (2) To achieve temporary plugging, the diameter of particulates should not be less than half of the fracture width under the condition of larger fracture width (≥4 mm). (3) The fracture surface morphology affects the formation time of temporary plugging, but does not affect whether temporary plugging is formed or not. (4) Using a steel plate with a smooth fracture surface to conduct optimization experiments will increase the dosage of diverters, thus increasing the operation cost. (5) Pure particulates cannot achieve favorable plugging effect. This study provides an insight into multistage acid fracturing.

Research on Horizontal Well Development Effect Assessment in Super-Low-Abundance Thin Reservoir

2012 ◽  
Vol 524-527 ◽  
pp. 1261-1265
Author(s):  
Bin Nie ◽  
Yue Tian Liu ◽  
Ting Jing Zhang
Keyword(s):  
Evaluation System ◽  
Horizontal Well ◽  
Comprehensive Evaluation ◽  
Fuzzy Comprehensive Evaluation ◽  
Evaluation Approach ◽  
Analysis Process ◽  
Statistical Analysis Method ◽  
Well Development ◽  
Thin Reservoir ◽  
The Evaluation System

Based on the actual production data, this paper selected some evaluation parameters and established reasonable evaluation criterion for the horizontal well development effect in the ultra low-abundance and thin zone reservoir by using statistical analysis method，reservoir engineering analysis process and reservoir numerical simulation technology .In addition, a development effect evaluation system specially for the horizontal well development effect in the ultra low-abundance and thin layer reservoir was build up with the fuzzy comprehensive evaluation approach. Finally, the evaluation system were applied in several low-abundance and thin reservoir blocks. It was shown that the evaluation system can scientifically estimate the development effect of this kind of reservoir and has a practical application value.

Advanced Modeling Capability to Enhance Near-Wellbore and Far-Field Bridging in Acid Fracturing Field Treatments

2021 ◽  
Author(s):  
Abdul Muqtadir Khan ◽  
Denis Emelyanov ◽  
Rostislav Romanovskii ◽  
Olga Nevvonen
Keyword(s):  
High Resolution ◽  
Fluid Transport ◽  
Field Studies ◽  
Particulate Material ◽  
Injection Rate ◽  
Far Field ◽  
Field Scale ◽  
Fracture Width ◽  
Acid Fracturing ◽  
Modeling Approach

Abstract Different applications of fracture bridging and diversion are used regularly in carbonate acid fracturing without an in-depth understanding of the physical phenomena that dominate the processes involved in the bridging and diversion process. The extension of modeling capabilities in conjunction with yard-scale and field-scale experiences will increase our understanding of these processes. A robust multimodal diversion pill and polylactic acid fiber-laden viscous acid were utilized for near-wellbore and far-field bridging, respectively. Numerous field treatments demonstrated the uncertainty of achieving effective diversion. An existing multiphysics model was extended to develop functionalities to model diversions at different scale. Extensive laboratory testing was conducted to understand the scale of bridging and diversion mechanisms. Finally, a bridging yard test was designed, and field case studies were used to integrate all the branches. Field cases showed a diversion pressure up to 4,000 psi depending on perforation strategy, pill volume, and pill seating rate. Correlations showed the interdependence of multiple parameters in diversion processes. The field studies motivated modeling capabilities to simulate the critical diversion processes at high resolution and quality. The model simulates diverting agents that reduce leakoff in the fracture area and their effects on fracture geometry. The approach considers the acid reaction kinetics coupled with geomechanics and fluid transport. Different diverting agent concentrations required for bridging can be modeled effectively. A yard test was designed to confirm the integrity of the pill material through completion valves (minimum inside diameter 9.5 mm) and analyzed with high-resolution imaging. All the theoretical, mathematical, and numerical findings from modeling were integrated with laboratory- and yard-scale experimentation results to develop and validate near-wellbore and far-field diversion modeling. Analytical correlations were formulated from injection rate, particulate material concentration, pill volumes, fracture width, etc., to incorporate and validate the model. This study enhances understanding of the different diversion mechanisms from high-fidelity theoretical modeling approach integrated with a practical experimental view at laboratory and field scale. Current comprehensive research has significant potential to make the modeling approach a reliable method to develop tight carbonate formations around the globe.

Neural Foundations of Variability in Attachment

2017 ◽  
Author(s):  
Allyson J. Bennett ◽  
William D. Hopkins ◽  
Ruth Feldman ◽  
Valeria Gazzola ◽  
Jay Giedd ◽  
...  
Keyword(s):  
Brain Development ◽  
Animal Studies ◽  
Experimental Studies ◽  
Theory Development ◽  
Single Type ◽  
Negative Consequences ◽  
Cultural Contexts ◽  
The Social ◽  
Insight Into

Neuroscience offers insight into processes that support the development of the social brain within the cultural contexts that permit attachment relationships to form. Both human and nonhuman animal studies are critical to inform theory development and hypothesis testing via descriptive and experimental studies. A scientifically valid evolutionary theory is necessary to account for the remarkable diversity of parenting systems across human and many nonhuman animals. This chapter examines the neural foundations of attachment and poses critical questions that relate to the initiation of this relationship: How does attachment interface with brain development? What is the interplay between attachment and brain development (including elements of bidirectionality)? Are there negative consequences associated with variation in attachment, and are they reversible? Rather than conceptualizing attachment in terms of a single type of relationship, or a rigid developmental channel, this chapter proposes that an expanded consideration of variation is necessary to understand the neural foundations of infant-caregiver relationships, and the role of those relationships in developing competence across the life span. This approach will permit identification of common neurobiological elements of attachment as well as the remarkable plasticity and diversity within and across individuals, cultures, and species.

Simulation of Multistage Acid Fractures in Horizontal Well Using Multiple Grid Geometry: Tight Carbonate Reservoir Case (Russian)

2020 ◽  
Author(s):  
Ignatiy Volnov ◽  
Danny Rojas ◽  
Assem Bibolova ◽  
Kok-Thye Lim ◽  
Jerome Amiotte
Keyword(s):  
Horizontal Well ◽  
Carbonate Reservoir ◽  
Tight Carbonate

Productivity-Prediction Model of Acid Fracturing Horizontal Well in Fracture-Cavity Reservoir

2013 ◽  
Vol 321-324 ◽  
pp. 872-876
Author(s):  
Yang He ◽  
Yong Ming Li ◽  
Jin Zhou Zhao ◽  
Ye Zhang ◽  
Tao Lin ◽  
...  
Keyword(s):  
Prediction Model ◽  
Horizontal Well ◽  
Material Balance ◽  
Production Capacity ◽  
Basic Principles ◽  
Acid Fracturing ◽  
Oil Storage ◽  
Cavity System ◽  
Seepage Theory ◽  
Productivity Prediction

Due to the particularity of the fracture-cavity reservoir space, the seepage theory developed from homogeneous reservoir cant be applied to predict the productivity of fracture-cavity reservoir. This paper simplified the fracture-cavity system to an oil storage vessel, and based on the basic principles of material balance, established the productivity-prediction model which was suitable for the acid fracturing horizontal well in fracture-cavity reservoir. The results showed that the productivity of fracture-cavity system was high and steady. Meanwhile, the connected fracture-cavity system had a greater contribution to increasing production capacity than other factors.

Three Dimensional Fractography of Extruded Age-Hardened Al Alloys Subjected to Fatigue Tests

2018 ◽  
Vol 940 ◽  
pp. 89-93
Author(s):  
Yuzo Nakamura ◽  
Ryuichi Iwamoto ◽  
Yuta Kurigeno ◽  
Hiroki Kamibayashi ◽  
Kohji Kariya ◽  
...  
Keyword(s):  
Fracture Surface ◽  
Crack Initiation ◽  
Three Dimensional ◽  
Fatigue Tests ◽  
Al Alloys ◽  
Metal Fatigue ◽  
Crack Initiation And Propagation ◽  
Initiation And Propagation ◽  
The Difference ◽  
Insight Into

Observation of fracture surface in metal fatigue is one of the most significant procedures to get insight into the cause and mechanism of crack initiation and propagation. In the present study, age-hardened 2017-T4 and 7075-T6 Al alloys having the extrusion texture were fatigue tested in low and high humidities, and their fracture surfaces were examined using a three dimensional (3D) surface analyzer. In addition to the microscopic observations conducted, it is shown that these 3D analyses provide important information on the difference in crack propagation depending on the stress level and environment.

scholarly journals From Symptom Tracking to Contact Tracing: A Framework to Explore and Assess COVID-19 Apps

2020 ◽  
Vol 12 (9) ◽  
pp. 153 ◽  
Author(s):  
Abinaya Megan Ramakrishnan ◽  
Aparna Nicole Ramakrishnan ◽  
Sarah Lagan ◽  
John Torous
Keyword(s):  
Evaluation System ◽  
Personal Information ◽  
End Users ◽  
Contact Tracing ◽  
Current Status ◽  
Privacy Concerns ◽  
Short Period ◽  
Insight Into ◽  
Health Applications ◽  
Comprehensive Study

Smartphone applications related to coronavirus disease 2019 (COVID-19) continue to emerge and evolve, but despite a wide variety of different app functions, there has yet to be a comprehensive study of what the most prevalent publicly available apps provide, and there exists no standardized evaluation system for end users to determine the safety and efficacy of an app before they download it. Furthermore, limited oversight means that the rapidly growing space creates challenges for end users trying to find a relevant app. We adapted the M-Health Index and Navigation Database (MIND) from apps.digitalpsych.org that previously has been used to evaluate mental health applications to guide the assessment of COVID apps. Using this framework, we conducted a thorough analysis of the top-100 returned coronavirus apps on two separate dates a month apart to understand the clinical utility and features of COVID-19 apps and how these change in a short period of time. We ultimately identified a significant turnover rate, as well as privacy concerns around lack of privacy policies and disclosure of personal information. Our research offers insight into the current status of COVID-19 apps and provides a comprehensive and adaptable framework to help individuals assess the growing number of such digital tools in the wake of the pandemic.

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