Advances in oil and gas technology are all around, increasing the amount and scope of discoveries with every passing year. Drilling, imaging, extraction, sample analysis—all of these areas and more are feeling the effects of technology research and development, with new discoveries giving rise to new interactions between sectors and almost instantly bringing forth ideas for even more.
Technological Overview of Drilling Techniques
The oil and gas industry relies on technology more than ever. From its’ beginning in the middle of the 19th Century, most people have the following image in their minds about oil drilling—a single oil derrick sinking a single oil well sinking a well straight down and striking oil in a very short distance. The oil is in a very circular bubble and can be removed very easily. The reality is that some oil is easy to get while most is not. From the simple oil-drilling rig, many new ways of extracting oil have been developed and enhanced over the years.
The first innovation is Horizontal Drilling. This is just as it sounds. A vertical well is turned horizontal while it is inside the reservoir rock, in order to expose more of the open hole to the oil. These turns are called “legs” and can extend for up to a mile. The longer the leg, the more oil or gas can be drained, and at a faster rate. The advantage of this is twofold. The first is financial—more oil can be produced using fewer wells. The second is environmental. There is much less surface area disturbed. The main disadvantage is that there are a very limited number of locations where this technique may be employed, according to Popular Science.
The next alternative form is called Multi-Lateral Drilling. This kind of drilling is used because there are instances in the same site where oil and gas are located at different points in different layers of rock. It allows the extraction of oil at different depths. More so than horizontal drilling, multi-lateral drilling dramatically reduces the number of actual wells needed for any given field. It has the same advantages and disadvantages as horizontal drilling.
Extended Reach Drilling
Extended Reach Drilling is a method in which producers can reach oil and gas that is extremely far away from the actual rig itself, said the website Rigzone. It is the directional drilling of very long horizontal wells. Its aims are to reach a larger area from one surface drilling location and to keep a well in a reservoir for a longer distance in order to maximize its productivity and drainage capability. The disadvantages can be any of the following: it is costly, hole cleaning can be difficult, as well as managing the mechanical loads on the drill string and managing down hole pressure, informs American Oil and Gas Magazine. Despite these problems, this type of well is outstanding for getting to deposits that are in areas you ordinarily could not drill—deep ocean or a built-up habituated area.
The definition of an Extended Reach Drilling (ERD) well is open to debate. ERD wells can be defined by their step-out/vertical depth, 2 to 1 ratio. This definition does not fit however, for deep water environments. The most common definitions are shallow, intermediate, deep, and ultra-deep. They can also be distinguished between deep water and high-pressure/high-temperature environments. The definition of extended reach varies over time and location and with the development of technologies and experiences.
Complex Path Drilling
Complex Path Drilling consists of drilling complicated directional wells in order to reach two or more accumulations using a single well. This technological advancement came through the development of stronger and more flexible materials for making drilling equipment as well as fiber-optic imaging to direct this equipment.
Hydraulic Fracturing or “fracking” is possibly the most profitable, while at the same time most controversial way of harvesting energy. It allows producers to safely mine natural gas and oil from deep shale formations. It has the potential to significantly reduce the planet’s co2 emissions and accelerate our transition to a carbon-light environment. Deep shale gas and oil formation development is critical to meeting the world’s energy needs and economic renewal. Simply put, “fracking” is injecting a liquid mix that is 99% water and sand into the shale at very high pressure. This creates fractures, (hence the name), within the rock that allow the oil and gas a path to get to the well-head. The fracking fluid also aids in keeping the rock porous. Hydraulic Fracturing is one of the most widely used methods to extract oil and gas. In the United States, for example, more than 90% of all wells have used this method to boost production at some time.
History of Drilling Technology and its Implications
The concept of horizontal drilling as well as other drilling applications is not a new one, which stemmed the idea that a well need not be absolutely vertical. This idea became widely known as far back as the 1920s when the first lawsuits began to appear between owners of adjacent fields when one owner was accused of either accidentally or on purposefully stealing the oil or gas under the other’s property, reported The Economist). In 1990, Iraq accused Kuwait of stealing oil in this manner. The first lawsuits used proxy evidence such as production changes in other wells. However, with the need for better surveying, miniaturized tools were invented for surveying wells while drilling. Directional drill rigs are heading towards large-scale micro-miniaturization, mechanical automation, hard-stratum working and exceeding length and depth-oriented monitored drilling.
To measure the inclination of a well-bore, (deviation from the vertical) is simple—you only need a pendulum. Measuring the azimuth, (direction with respect to the geographic grid in which the wellbore was running from the vertical). Magnetic fields could be used, but could also be thrown off by the metal in the well and drilling equipment, informs Rigzone. The next advance was the development of a small gyroscopic compass by the Sperry Corporation. Sperry was using the same line of research for aeronautical navigation. For this technology, three components are measured at any given point in the well bore in order to determine its position—the depth of the point along the course of the borehole (measured depth), the inclination at the point and the magnetic azimuth at the point. These three components are referred to as the “survey”. A series of these surveys are used to track distance and direction.
In 1934, H. John Eastman became a pioneer in directional drilling when he and a man named George Failing saved an oilfield on Conroe, TX that was experiencing a blowout, as reported in American Scientist. Failing has recently patented a portable drilling truck. This new invention allowed the rapid drilling of a number of small, slanted wells. Drilling a small number of “relief wells” was crucial in controlling what was becoming a rapidly out-of-control blaze. Tools such as these and single-shot technology continued to improve steadily, but were seen as only for use in strange or emergency situations. The next major advance in what had become known as Bottom Hole Assembly (BHA) was in the 1970s, when down hole drilling motors became common. These “mud motors” were driven by the hydraulic power of drilling mud circulated down the drill string. These allowed the drill bit to continue rotating the cutting face at the bottom of the hole, while most of the drill pipe was held stationary, said an article from Popular Science. A “best sub” or piece of bent pipe is placed between the stationary drill pipe and the top of the motor allowed the direction of the wellbore to be changed without needing to pull the entire drill pipe out and place another whipstock. Directional drilling became easier with the development of “measurement while drilling tools”—tools that used mud pulse telemetry, networked or wired pipe or EM telemetry—which allow the down hole location to send directional data to the surface without disturbing operations, according to Popular Science.
The advantages of these modified and improved drilling techniques are many. One is increasing the exposed section length through the reservoir by drilling through the reservoir at an angle. Drilling into the reservoir where vertical access is difficult if not impossible, if the oil field under a lake, a town, or other difficult-to-access location. It is advantageous to have more wellheads grouped together on one surface location. This allows for fewer rig moves, there is less surface area disturbance and it becomes easier and cheaper to complete the wells. Drilling along the underside of a reservoir constraining fault allows for multiple productive sands to be completed at the highest straitigraphic points. One of the most important points for safety is the drilling of relief wells to relieve pressure of a well producing without restraint, which is known as a blowout. Another well can be drilled starting at a safe distance from the blowout, but intersecting the troubled well bore. Then heavy fluid, or kill fluid, is pumped into the relief wellbore to suppress the high pressure in the original wellbore, informs Rigzone.
Directional Drilling and Horizontal Drilling are much slower than vertical drilling due to the need to stop regularly and take time-consuming surveys as well as the rate of drilling itself. These disadvantages have shrunk due to the fact that down hole motors have become more efficient, and semi-continuous surveying has become possible. The largest remaining problem is cost. For wells with an inclination of less than forty degrees, tools to carry out adjustments or repair work can be lowered by gravity on cable into the hole. In the case of higher inclinations, more expensive equipment must be used to push tools down the hole. The other major disadvantage of wells with a high inclination is that prevention of sand influx into the well was less reliable and needed more effort at a greater cost. This is a disadvantage that has shrunk due to technological advances, reports American Oil and Gas Magazine.
The Present and Future of Drilling
The current situation in Egypt today clearly illustrates the need for different ways of extracting oil and gas. The country is being pulled in two different directions to meet its power demands. The chances for domestic unrest are lessened by providing power to the people of the country itself, reducing the number of power blackouts and gasoline lines. At the same time, however, oil and gas needs to be exported in order to generate the needed funds to pay off international creditors, making Egypt a place that can receive foreign investment for new projects, according to Bloomberg. Being able to extract additional oil and gas from wells that are already located and being harvested vertically is paramount in the overall process. For the current uses of non-vertical drilling processes in Egypt today, RWE Dea and Apache provide good examples for companies who have been operating in Egypt for decades, and are using alternative drilling to obtain new benefits.
RWE Dea has achieved 30 years of oil exploration in the Gulf of Suez. The company has produced over 640 million barrels of crude over 3 decades. The company is making ongoing investments in modern technology and infrastructure to maintain these high production levels. RWE is optimizing operations in its oilfields. RWE Dea has been successful with the Ras Fanar field just a few miles off the west coast of the Gulf of Suez since 1984. Oil production at their other two concessions in the Gulf of Suez, Zeit Bay, and Ras Burdan, has been ongoing for 30 years. RWE Dea is currently developing the Zeit Bay oilfield using extended reach wells drilled from land in addition to the existing offshore wells. Currently they are also working the Zeit Bay field to optimize the “gas lift” system to increase oil production. This method involves capturing and processing the associated gas and injecting it through the annulus back into the wells to lift production, informs Hart Energy.
Apache Corp. (APA), the largest crude oil producer in Egypt, is expanding its drilling program, even as unrest rattles some investors. Apache is adding horizontal drilling and hydraulic fracturing to its portfolio of traditional wells as it targets new layers of dense rock in its Egypt oilfields.
Apache’s extended drilling program includes new horizontal wells, the first of which began producing in December 2013 with an average output of 2,000 barrels per day. Egypt’s geology compares to that of the Permain Basin region of West Texas, where Apache is a leading producer. There are some rock layers exploited easily with conventional methods and others that require newer techniques. The company has found that it can increase production from some fields by using traditional vertical wells to tap conventional reservoirs, then adding horizontal drilling and hydraulic fracturing to top denser, so-called unconventional layers of rock, says a report from Bloomberg.
Apache Corp has applied for licenses to develop two recent discoveries in the Western Desert of Egypt, where drilling now includes horizontal wells targeting conventional and unconventional resources. Last year Apache received approval of 20 leases converting short-term exploratory rights into 20-25 year development leases covering 66,000 acres. The company now has 119 development leases covering 2 million acres. Apache has 25 rigs at work in Egypt, including four drilling horizontal wells. Its exploration leases cover 5 million acres, according to OGJ Online.
The first well of a multi-well horizontal drilling program, AG-115 in Abu Gharadig field, has come on stream and produced averages of 1,681 b/d of oil and 3MMcfd of gas during December 2013. Production is from a 1,970 ft. lateral of a horizontal section in a 20 ft. oil zone in Abu Roash D Limestone. The well cost 6.5 million USD to complete.
A horizontal well targeting the Abu Roash G dolomite in Main Rozzak oilfield is being tested. Drilling is in progress on a horizontal well targeting Abu Roash G sandstone in North El-Diyur field, a horizontal well targeting Abu Roash G dolomite in North Ras Qattara field and two horizontal wells targeting the Upper Baha riya formation in Umbarka and Neama fields.
Apache said that the average production from its Abu Gharadig basin properties reached a record 55,214 boe/d gross in December, up 90% since acquisition of the assets in 2010.
By Curt ChampeonDownload