Recoverable oil

From an environmental audit on Block 3A and subsequent mapping throughout the whole field, the Team estimated that, in total, over 3 km2 was contaminated with oil in total at the time of assessment with over 2.5 million tons of recoverable crude in the ground. Local officials say that over 4.5 million tons had been spilled over the years due to ruptured and antiquated, pipelines and well drilling practices that allowed oil to accumulate in unrestrained pools during testing procedures (Fig 1). Several large accidents near the Primary Processing Unit resulted in the formation of an oil “lagoon” containing about 600,000 tons of recoverable crude. From an environmental standpoint, the main concern of such contamination is the effect on local air quality, ground water, animal and plant life, and landscape. The direct and indirect impact to human health was deemed minimal.

Due to the regions low precipitation, high summer temperatures, and strong wind (which limits inhalation concerns caused by escaping gases), the spilled crude does not deteriorate readily but rather forms a crust that effects the establishment of animal and plant life. Furthermore, indiscriminate driving and dragging of equipment between irregular positioned wells removed over 75% of vegetation cover. The resulting visual “wasteland” appearance of this on future generations is deemed considerable but is tempered by the field’s current isolated location. However, the production area does contain rather striking canyon-like weathered chalk landscape that may, in future, be further appreciated.

Fig 2. Gathering of spilled oil for treatment

Financial Benefits
The team’s first goal to confront this problem was prevention in the form of emergency response plans, training, and organization of needed equipment. Although such prevention is initially expensive, it is far more cost effective than e.g., unattended pipeline ruptures that had, in the past, leaked oil for days. The second goal, cleanup and economic recovery, was a much larger task (Fig. 2). Together with the UMG and KO staff, the E&E Team researched technologies that might be appropriate for this effort. They include:

• Bioremediation;
• Gravity separation;
• Water and solvent washing;
• Thermal desorption; and
• Road making material.

Fig 3. Oil waste treatment scheme

These technologies vary from simple to complex; the goal is to integrate advantageous aspects of each into an overall approach. In this regard, we have formulated a scheme for oil waste treatment (Fig 3). Depending on the effectiveness of the treatment scheme, the treated soil can be used for road material, plant growth media or to fill pits and trenches created by other activities. Based on the estimate of 2.5 million tons of recoverable waste oil and average net price UMG is receiving for their crude, we conservatively estimated that an additional income in excess of 30 million USD could be realized. This includes the cost of reasonable cleanup of the whole field, recovery and treatment of the crude. Moreover, the benefit can be enhanced by utilizing the less economically viable portion of oil sludge to produce asphalt. The asphalt would be used to repair and define the haphazard oil field road system and therefore reduce hazard to human health and impact to flora and fauna.

On average, the Team estimated that oil pits created during well testing and pipeline rupture may result in UMG loosing $30,000 USD per pit. The majority of this expenditure can be recovered if procedures on the collection and segregation of spilled oil developed by the Team are followed. These suggestions promote the best aspects of the currently used practices while incorporating innovative techniques and equipment suggested.

Дата добавления: 2014-01-07