Proven gas historically can enable us to attend the existing gas deficit.

Significant gas deposits can be found in the Sabana region.

Approximately time lecture:

5 minutes

History has proved that gas is present under the Sabana de Bogota region; we must seize the opportunity.

Introduction

As we delve into the current situation of Colombia´s energy security, we need to be aware of the current fires occurring all along the country, how this dry season will impact the water supply to each concerned region, and foremost, how it is going to enact a potential crisis on the energy creation on most of the hydroelectric power stations that base their output from water sources. In addition, our current plan b as an alternative, if hydroelectric runs out of water, the use of gas and coal for electricity generation becomes a solid option to prevent any shutdown, But due to the current context the country is facing regarding gas reserves, is clear, that we will be facing with an expensive and foreign gas input because we no longer have the capacity to count with our reserves.

Having said that, supplying the country with affordable energy will be an important task, so the only element that will be solid enough to provide reliable and consistent electricity generation will be coal. Luckily, our coal industry can provide enough supply in case of need, but let´s not forget that the use of gas after water results in a cleaner and less polluted mechanism for electricity generation.

Based on the current trend that Colombia has set throughout the years with its hydroelectric power plants, we cannot deny that the weather conditions after the summer of 2024 will impact this energy source. To ensure that our security remains on track, we will need to use coal as the only source left from our capacity unless the current Colombian government starts importing foreign gas to prevent coal reuse in energy generation.

However, as a group, we intend to provide significant solutions to the country that enable an alternative source to coal at this particular moment, as we have seen some considerable presence of gas in regions such as La Sabana de Bogotá. As a country, we must take this opportunity to explore existential areas where gas could be extracted to enable us to supply our entire nation with the necessary resources in need of gas. This opportunity has been proved in the past and could represent a solid option for energy sovereignty and clean energy generation after hydroelectric no longer manages to fulfill its mission.

Gas blew out during the Chingaza water supply tunnel construction that brought water to Bogota in August 1980.

As we prepare for a potential gas shortage in Colombia, it's essential to delve into the historical identification of gas resources. This knowledge will help us understand the potential benefits these resources could bring to our country's energy needs. A notable instance is the gas discovered during the construction of the Chingaza tunnel, located near Bogota, the capital city.

The Chingaza supply water system, which brings 14 cubic meters of water per second to Bogotá city through 36 kilometers of a tunnel, had several problems during its construction, among them a gas blowout that killed 26 people on August 18, 1980. The tunnel construction was started in the 1970s by the Yugoslavian company KONSTRUKTOR and ended by the Mexican company ICA in the 1980s.

The gas blowout happened when the tunnel crossed the high overmature organic interval Late Aptian in the age of the Fomeque Fm. (SWEET SPOT). The high free gas present in this interval forced the construction of a ventilator window to the surface. Despite that, daily gas lectures were in the order of 345,000 cubic feet of gas. Stratigraphically, the high organic overmature interval 650 feet in thickness is approximately 1000 feet underneath the Une Formation.

The presence of this high organic overmature interval (SWEET SPOT) was confirmed during the drilling of the Junin stratigraphic well drilled 12 kilometers apart from the tunnel in a northeast direction by NEXEN in 2012. The well was drilled for stratigraphic purposes at the edge of the Sueva syncline.

As organic matter matures, it can generate hydrocarbons and lead to further changes in rock structure, potentially enhancing porosity and creating secondary porosity through the breakdown of kerogen. The Eastern Cordillera has suffered high structural activity, inducing fracturing. As a result, the permeability and connectivity of pore spaces have increased, facilitating fluid flow.

The main characteristics of this organic interval (SWEET SPOT) found during the drilling of the Junin well are as follows:

The highly organic overmature interval of the Fomeque Formation (SWEET SPOT) could be reached in a high compressibility spot deepening or twinning the Sueva well (NEXEN 2011) located 10 kms apart to the west of the Junin well and drilled at the core of the Sueva Sinclinal.

The Sueva well reached the high organic anoxic Turonian sweet spot 750 foot thick in the basal part of the Chipaque Formation. The well had a gas flare of 20 minutes during drilling of this interval. Gas up to 168.000 ppm with a mud weight of 9.3 ppg

The Sueva syncline is 65 kms long and it is estimated to hold 40 - 50 TCFs at the Chipaque and Fomeque formations (ANH 2020). It is recommended to reach vertically the Chipaque and Fomeque Formations at the axis of the syncline and navigate 1 or 2 kms horizontally along these organic intervals.

The Suesca well located 20 kms apart in a NW direction of the Sueva well is another indication of a free gas at the basal part of Chipaque stratigraphic level. The well was drilled by EXXON in 2009 and tested 1.2 - 2.0 MM cfg without any hydraulic stimulation.

Conclusions

There is no doubt that free gas is present in the highly organic mature interval identified at the top of the Fomeque Formation during the construction of the Chingaza water supply tunnel, causing a gas blow that killed 26 people back in 1980.

The free gas is due to the transformation of the organic matter at high thermal maturity, which has enhanced porosity and permeability values in this interval. As the cordillera has suffered high tectonic events, fractures have increased porous interconnection, helping fluid connectivity.

A ventilator window was needed to control the gas presence during the excavation of that tunnel. The same highly organic interval (650-foot thickness) was identified during the drilling of the stratigraphic Junin well at the edge of the Sueva syncline.

The Sueva syncline, a location of paramount importance, is situated 10 kilometers west of the Junin well. It is a critical player in gas exploration, offering a wealth of potential. To tap into its resources, the Sueva well will need to be deepened or twinned to reach the best compressibility spot. Vertical wells should be drilled along the syncline's axis to reach the Fomeque Formation, followed by a horizontal well 1 -2 kms in length to navigate the organic interval without hydraulic stimulation. The sweet spot at the basal part of the Chipaque could serve as an upside in the gas accumulation beneath the Sabana de Bogota.

Given the impending gas deficit that Colombia is likely to face in the coming years, it is crucial to explore alternative energy sources. It is important to review where these mentioned gas evidences have been historically identified and start visualizing how these potential resources could benefit the country.

The time to act is now.