Unconventional Gas Development - Essay Example

Unconventional Gas Development Currently, the whole world around has extremely high demands for energy. This has brought up a crisis in that, its demand and consumption rates supersede the supply and rate of discovery. The shortage thereof, has called for the world to look for alternative resources of energy other than oil and gas reserves. They settled for the unconventional gas resources and its development; due to its environmental benefits, attractive prices, long-term potential, current advancement in technology and the never ending demand for gas (Zahid 2) Some experts believe that by 2025, gas consumption then put in consistent units of barrels of oil equivalent per day (BOE/D)³ would have exceeded that of oil. Current status of unconventional gases Unconventional gas refers to gas produced from unconventional sources for example, tight gas, geo pressured as, deep earth gas, shale gas and methane hydrates; but its main constituent is methane. But for commercial purposes, shale gas, coalbed methane and tight gas are the ones being produced. China, Central Asia, North America and Former Soviet Union have the largest unconventional gas resources but currently, USA has the largest production volumes and account for 41% of the total natural gas production since it has advanced technology and better economic growth patterns. China too, has both high population and economic growth leading to an extremely high and steady increase of demand for energy supply (Flores 3). This has led to the Chinese intensifying their exploration efforts for the unconventional gas resources, by building nation-wide trunk lines i.e. the Shan-Jing gas pipeline, Zhong-Wu pipeline and the west-to-east gas pipeline; constructing gas storage facilities and encouraging international corporations to participate by adding more blocks to attract foreign investors to bring specific technologies and managerial skills for unconventional gas development (Hongjie 3). With all these efforts put in place and the many volumes of gas in unconventional resources, China still faces a challenge in developing unconventional gas, since it lacks some extremely vital tools in their market. Some of the tools they lack and which they are as fundamental in unconventional gas development include: the PCM (Precision Continuous Mixers) used for providing gelled fluid to the blender; the snubbing unit which is used for controlling wellhead pressure for unbalanced completion and workover operations; UBD (Under Balanced Drilling equipment) pressure control for use in low pressure, naturally fractured and unconventional reservoirs; and compressors. Unconventional oil and gas are abundant, but their exploitation is sensitive to both technology and commodity prices. The Master’s resource triangle theory (RTT) which suggests that natural resources are distributed log-normally perfectly explained this. This means that the high-quality resources are produced in low quantities and are located at the apex of the triangle whereas the low-quality resources are large in quantity and are located at the base of the triangle. This was the theory used for the justification of why western Canada increased their gas reservoirs and how large, low-quality deposits may be developed as commodity prices get higher and improved technologies become available. At the moment, scarce high-quality deposits are called conventional reservoirs and large low-quality deposits are called the unconventional reservoirs e.g. tight sands, gas shales or heavy oil; and are increasingly getting popular since the demand for oil and gas is steadily increasing on a daily basis and conventional gas development declines. . Characteristics of unconventional gas Each type of gas resource has its unique characteristics hence the call for a specific extraction and development process. But they all share a common characteristic which is, they all have a low flow rate due to low permeability in the reservoirs. Examples of the unconventional gases and their development include: Tight gas sands They are characterized by low permeability due to the digenesis that has filled the pores with quartz and clay overgrowths. Due to this, it requires high hydraulic fracturing treatments to attain commercial production rates. Coalbed Methane (CBM) Methane is the primary gas in these reservoirs and is usually stored as adsorbed gas on the internal surfaces of coal. Factors that influences the gas content are; the rank of the coal, pressure of the reservoir and the depth of the burial in the coal bed. Different completion techniques are used depending on the type of coal, continuity, porosity and permeability of gas. Examples of the techniques used are: vertical drilling and fracture heating; horizontal and multi-lateral wells. Shale gas Shale gas reservoirs are both the source rock and the reservoir rock. Normally, it is adsorbed in organic matter and is released via desorption by reducing the pressure. The horizontal and multi-lateral drilling techniques are used in the production of shale gas (Willigers 2). Unconventional gas resource assessment During the development of unconditional resources, different techniques are used. For example, for one to drill a new area, he has to perform a basin assessment in emerging basins, extended reservoir characterization and in addition to these, conduct studies to evaluate tectonics and natural fracture patterns in the basins or plays. For maximum benefits of such projects, both the drilling project and the gas infrastructure development should be optimized. This is achieved by laying down a set of objectives, constrains and tradeoffs since there is no single practical method to use on all the reservoirs. To achieve the best optimization in unconventional gas development, various calculations of a genetic algorithm that is conditioned with Bayesian logic are used (Willigers 1). Genetic Algorithm is a technique that uses the genetic algorithm principles inspired by evolutionary biology whereas Bayesian Logic makes if fundamental that a decision maker has to reassess point-forward decisions upon the arrival of fresh information and then three optimization runs are performed in order to reach an outcome. However, many unconventional gas development projects are slightly economic. The energy team behind the decision making must understand the correlation between the different drilling schedules and infrastructure. How they affect their set goals and also what constrains they tag along. The use of genetic algorithms has become a proven technique to optimize complex non-linear systems hence can be used to find an optimal area for the development of unconventional gas reservoirs. Time is the ultimate solution for all issues in that many developmental projects are faced with multiple decision making hurdles and uncertainty but all these are gradually resolved over time. Conclusion The resource triangle concept states that; “oil and gas production from low-permeability reservoirs increase with rise in commodity prices (Masters 152). This was confirmed from a study correlating the relationship between economics and development of technology and came up with the results showing that there is an increase in drilling rig activity when the commodity prices are high. There is also an increase in unconventional gas development by the use of both the vertical and horizontal wells. Work cited Flores, P. et al. Economics and Technology Drive Development of Unconventional Oil and Gas Reservoirs: Lessons Learned in the United States. SPE, Texas A&M University, 2011 Hongjie, Xiong et al. Will the Blossom of Unconventional Natural Gas Development in North America Be Repeated in China? Burlington Resources and Texas A&M University, 2006 Masters ,J. Deep Basin Gas Trap, Western Canada. AAPG Bulletin 63 (2): 152-181 Willigers, J. Optimization of Unconventional Gas Developments by Bayesian Logic and Genetic Algorithm. Palantir Economics Solutions Ltd, 2011 Zahid, S. et al. Development of Unconventional Gas Resources: Stimulation Perspective. University of Engineering & Technology, Lahore, Pakistan, 2007 Read More