Tuesday, June 26, 2012

Subject Specific Challenges to Making Science Labs Work

Most students do not go on to become scientists and for these students the main goal of science education should be to teach rigorous, evidence-based thinking and to convey a sense of wonder about the natural world. These goals can be met by any branch of science; there is no obvious reason why biology would be better than physics or Earth science would be more important than chemistry. Indeed, it is undoubtedly possible to point to curriculums and classes in all areas of science that do a wonderful job of teaching scientific thought. However, that doesn't mean that it is equally easy for teachers to meet these goals in every domain.
It is clearly important for students to have real, meaningful laboratory experiences in science classes. It is possible to have great labs in all branches of science but the challenges can be quite different. One of the big challenges in biology is that experiments often take an extended period of time. Frequently, getting results is simply not possible in a single, 45 minute class period. Even with 1.5 hour double periods, designing biology experiments that fit can be difficult. On the other hand, working with animals (and even plants, fungus, and protists) is inherently motivating and exciting for most students. Furthermore, many of the most important ideas in biology are less abstract and mathematical than the big ideas in physics and chemistry, and are therefore easier for many students to absorb.
In contrast, physics labs often get much quicker results than biology labs and can have the advantage of being visually dramatic. The difficulty for physics teachers is bridging the gap between the labs and the principles which they demonstrate. It's no secret that physics involves quite a bit of math and many students get so caught up in their struggles with the math that they are unable to see the ideas behind the formulas. One of the most successful solutions to this difficulty is conceptual physics classes, which are often successful in helping students understand the big ideas of physics.
Chemistry labs also tend to be quick enough to fit into class periods and they are often very exciting. Indeed, the most common request I get as a science teacher is for "explosions" which are almost entirely the domain of chemistry. With chemistry labs, the duel challenges are safety and connecting the macroscopic results with the microscopic reasons behind the results. Safety in chemistry labs is often best addressed by having well-designed, dedicated lab rooms in schools. When that is not possible, work-arounds using household chemicals instead of their more exciting and dangerous counterparts are sometimes possible. Connecting lab results with the actions of molecules is becoming easier for teachers as better and better computer simulations for chemistry education are developed.
Earth science is the fourth major branch of science and it is the most forgotten one. In some ways it is the broadest of the subjects; any study of earth science will inevitably touch on aspects of chemistry, physics, and biology. Designing earth science labs is quite challenging because it is impossible to actually manipulate landforms or weather in the classroom. For this reason, earth science labs rely strongly on models. Reliance on models can be a strength if it is used as an opportunity to really explore the place of models in science or it can be a weakness if simple models are used as stand-ins for complex systems without discussion.
Each branch of science has its own advantages and disadvantages from the point of view of a teacher designing a curriculum with a strong, relevant, and exciting laboratory component. For most students, it is not especially important which branch (or branches) that they study; rather it is important that they learn scientific thinking and evidence-based reasoning.

Monday, June 4, 2012

Drilling and Producing Crude Oil and Natural Gas

This article demonstrates how crude oil and natural gas wells are drilled.
One of the main questions is how do we find the traps where these natural resources are found? Years ago it was based on the ancient strategy called "luck". Producers would simply drill one well right at the side of another; there were no scientific methods, just simple guess work. By doing this the landscapes really suffered.
Today the good luck and guess work have been replaced with science and technology, the same technology and principles that are used for drilling in Alaska, Texas, and Oceans and even in the Middle East.
Suppose a geoscientist finds a possible trap, meaning that potentially there is either crude oil or natural gas in that location. This presents us with some common questions.
First, are there giant pools of crude oil and gas under the ground or do we get it from certain rock formations?
Secondly, how do we extract that natural resource from the earth and create energy out of it?
Once the geologist find a trap that could contain crude oil and gas a drilling rig is brought in.
What is a drilling rig and how does it work?
The drilling rig is a piece of equipment that is brought onto the rig for five or six or seven days which drill a hold about the size of a football and is capable of drilling down several thousand feet down into the earth's surface. Once the hole is drilled a variety of sensitive instruments called logging tools send electronic messages that provide a detailed record of the rock and fluid properties of the geologic formations.
A typical rotary drill rig goes about 5,000 feet down. Imagine taking 16 football fields and placing them end to end and turning them upright, that's about 5,000 feet. 
The rigs process is very similar to drilling through a piece of wood, only the drill bit is about the size of the football we mentioned earlier. The drilling is performed by highly trained members of a drilling crew.

Once the rig has drilled through various rock formations, steel piping is placed in the ground, then a cement shield is placed around the pipe to protect any water table or aqua furs, the piper is then perforated a and fractured only at the crude oil and natural gas rock formation to allow the flow of these vapours and liquids to move up the well to the surface. If the rock formation contains enough crude oil and or natural gas the rotary drill rig will be replaced with a pumping unit. Now the purpose of this is to keep the crude oil and natural gas flowing. Crude oil is sent into storage tanks and natural vapours are sent into vapour pipelines.
Often times today we need a drill in areas that won't allow us to drill down straight vertically, but with some of the latest technologies we are now able to drill directionally, this is an excellent way, for example to drill under a park or a school's property, many pre-developed areas tend to be a great place for crude oils r natural gas so the directional drilling technology is a great way to retrieve the source.
So what is the cost?
The costs usually ranges from 350,000.00 to 1, 000, 00.00 and an offshore well can cost up to a billion dollars per well and there's still no guarantee it will even produce.
I'll now use Ohio, USA as a case study
In Ohio there is over 64, 00 crude oil and gas wells producing in 49 of Ohio's 88 counties, with more than 273, 00 well drilled.
Do all Ohio counties produce crude oil and natural vapours?
The answer is no! The potential geological formations that contain crude oil and gas simply do not exist throughout the state which is why technology plays such a key role in retrieving this vluable rescource.
Now back to a question asked at the beginning of this article -
Once we have drilled to our targeted rock formations, how do we get the crude oil and natural gas out?
Utilising scientific principles of movement the fluids, crude oil and vapours are lifted out of the ground to the surface using a variety of different pumping units. How do these units work? Well first of all kepp in midn that if a pump jack is not moving then it doesn't mean that a well is not producing. The pump is just turned on long enough to create a syphoning effect. Petroleum engineers, production supervisors or well tenders will typically determine how long each individual well should be turned off and on. Also, keep in mind that the motor on this pumping unit also need energy to work. This energy is either the well's own gas source or electricity or solar panels. If electric is used the pumping units may be switched on overnight during off-peak electric times.
Where does it go when it's out of the ground? The first place it will go into will be a separator, the separator separate the crude oil liquids from the gas vapours. the crude oil when then move onto a storage unit called a Tank Battery and the vapours will be transported through a number of Natural Gas Pipelines for distributions.
Why can't you always see these crude oil and gas wells? New technology allows us to have a very small environmental footprint. These wells are hidden by plants and other landscaping like and can be found in car parks or in back yards if schools, churches, cemeteries, parks, cornfields or even your own back yards and these wells can produce energy for decades.