Preparation of silica-coated gadolinium compound particle colloid solution and its application in imaging

Abstract Drilling in permeable formations, especially depleted reservoirs, can particularly benefit from simultaneous wellbore shielding and strengthening functionalities of drilling mud compounds. The ability to generate simultaneous wellbore shielding and strengthening in reservoirs has potential to widen stable mud weight windows to drill such reservoirs without the need to switch from wellbore strengthening compound to wellbore shielding compound, and vice-versa. Wellbore shielding and strengthening experiments were conducted on three outcrop sandstones with three mud compounds. The wellbore shielding stage was conducted by increasing the confining and borehole pressures in 4-5 steps until both reached target pressures. CT scan images demonstrate consistency of the filtration rates with observed CT scanned mud cakes which are dependent on the sandstone pore size and mud compound particle size distributions. In wellbore strengthening stage, the borehole pressure was increased until fracture was initiated, which was detected via borehole pressure trend and CT scan imaging. The fractures generated were observed to be plugged by mud filter solids which are visible in the CT scan images. The extent of observed fracture solid plugging varies with rock elastic properties, fracture width and mud compound particle size distribution. Based on the laboratory test data, fracture gradient enhancement concept was developed for the mud compounds. In addition, the data obtained and observations from the tests were used to develop optimal empirical design criteria and guidelines to achieve dual wellbore strengthening and shielding performance of the mud compounds. The design criteria were validated on a well which was treated with one of the mud compounds based on its mud loss events during drilling and running casing.

Download Full-text

Rubber Modified Asphalt Mixture Properties and Mechanical Testing

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.105-107.810 ◽

2011 ◽

Vol 105-107 ◽

pp. 810-817 ◽

Cited By ~ 2

Author(s):

Rong Hui Zhang ◽

Jia Liu ◽

Jian Chao Huang ◽

Yi Fu

Keyword(s):

Asphalt Pavement ◽

Asphalt Mixture ◽

Asphalt Mixtures ◽

Specimen Preparation ◽

Twin Screw Extrusion ◽

Modified Asphalt ◽

Flexural Tensile Strength ◽

Screw Extrusion ◽

Twin Screw ◽

Compound Particle

To solve the high-temperature rutting problem of asphalt pavement, the old rubber of the tire rubber and plastic of general polyethylene waste composite modified asphalt mixture is proposed. The plastic and rubber compound particle was made by the rubber through efficient desulfurization additives, pre-swelling, twin-screw extrusion equipment. The particles mixed with the asphalt mixtures specimen preparation and the dynamic stability experiments, composite beam fatigue experiments, flexural tensile strength and modulus experiments and anti-reflective pavement cracks and other mechanical experiments are performed. The comparative data obtained by the rubber and plastic composited modified asphalt mixtures and SBS asphalt mixtures prove that the rubber and plastic composited modified asphalt mixtures have excellent rutting resistance and fatigue resistance.

Download Full-text

Analysis of Students’ Critical Thinking Skill of Middle School through STEM Education Project-Based Learning

Jurnal Pendidikan IPA Indonesia ◽

10.15294/jpii.v7i1.10495 ◽

2018 ◽

Vol 7 (1) ◽

pp. 54-65 ◽

Cited By ~ 16

Author(s):

L. Mutakinati ◽

I. Anwari ◽

Y. Kumano

Keyword(s):

Middle School ◽

Critical Thinking ◽

Stem Education ◽

First Grade ◽

Project Based Learning ◽

Colloid Solution ◽

Design Solution ◽

Thinking Skill ◽

Critical Thinking Skill ◽

School Students

This research is to investigate the students` critical thinking skill by using STEM education through Project Based Learning. The study applied descriptive research design. In these lessons, the participants were 160 first grade Japanese middle school students from four classes. They were divided into nine groups each class. The instruments are worksheets to explore students’ initial knowledge about how to clean up wastewater and critical thinking processes. The worksheet consists of the designing solution, and understanding of concepts to identify critical thinking based on purpose and question, selection of information, assumption, and point of view the solution, and implication. Students were asked to design tools to clean up the wastewater. Students were given more than one chance to design the best product for wastewater treatment. The lessons consist of six lessons. The first lesson is the introduction of colloid, solution, and suspension, and discussion about wastewater. The second lesson to the fourth lesson was finding solutions and designing products. The fifth lesson was to watch a video of wastewater treatments in Japan and to optimize the solutions or products. The last lesson was to make a conclusion, to exchange presentations, and to develop discussion. Implementation of STEM education can be seen from the students` solutions, some students used biology or chemistry or physics or combination concept and Mathematics to design solution (technology) for treatment of wastewater. The result showed that the mean score of students` critical thinking skill was 2.82. The students` critical thinking skill was categorized as advanced thinker: 41.6%, practicing thinker: 30,6%, beginning thinker: 25%, and challenged thinker: 2.8%. And the category for students` critical thinking was practicing thinker. Practicing thinker is a stage of critical thinking development, they have enough skill in thinking to critique their own plan for systematic practice, and to construct a realistic critique of their powers of thought to solve the contextual problem.

Download Full-text