It is very important to determine the characteristics of the nature of geological faults in the stage of production and exploration of hydrocarbons. However, there is no cost-effective methodology to determine the sealing or non-sealing character of a geological fault. There are methods to determine these characteristics, which have some drawbacks, e.g., it is required to maintain the production conditions of an oil well at a constant flow rate or to shut down the production of the well, which entails operating expenses for the period of time that the well is not in production. The objective of this study is to develop a cost-effective and environmentally sustainable methodology in order to determine the effect of geological faults (i.e., boundary effect). Therefore, a water well was located near the geological fault and the pressures that were measured during transient pressure tests were recorded, the benefit obtained by performing a water well was the speed of the pressure response, which It is transmitted more quickly, due to the characteristic of the fluid.
Top1. Introduction
In the first months of 2009, an increase in well drilling permits was observed in the United States, which lasted until the beginning of 2015(Vera R., 2016), In consequence, debate grew on the benefits and environmental consequences of hydraulic fracturing (Raimi D., 2017). Besides of the benefits that the increase in hydrocarbon extraction entails through this process, such as: Increased income and employability(Bartik A. et al., 2019), there are many negative consequences of hydraulic fracturing; 1) Consequences to Human Health: Effects on human health for workers and people living near well platforms, new cases of asthma with the development of unconventional reservoirs(Rasmussen S. et al., 2016) ; 2) Consequences for the fauna: Release of gases in the aquifers that would have a polluting effect on farmed animals.(Bamberger M. & Oswald R., 2012) 3) Environmental Consequences: Changes in air quality because these chemicals can have long-term effects(Colborn T., 2011);Methane gas leaks and toxic chemicals seeping from the well(Osborn S. et al.,2011);High concentration values Methane, Ethane and propane in drinking water wells near the hydraulic fracturing zone (Jackson R. et al., 2013); Surface-level spills of hydraulic fracturing fluids in significant volumes and concentrations as a result of operational accidents that reach aquifers or groundwater (Environmental Protection Agency, 2016). Besides, exist Circumstances (causes) where hydraulic fracturing would affect drinking water sources a) Fluid seepage through activation of geological faults(Reagan M. et al., 2015), b)Poor design or operational failure of the casing cementation would result in a leak of hydraulic fracturing fluids(Darrah T et al.,2014), c) Terrible stimulation techniques(Reagan M. et al., 2015) d) Water consumption in areas or times of the year with low water availability.(Environmental Protection Agency, 2016) then it shows in Figure 1 the potential routes that would lead to the contamination of an aquifer: poor operation in the cementation of the casing pipe, migrations of drilling fluids through geological faults to an aquifer. 4) geological consequences: induced seismicity (Hong Z. et al., 2018) in a space-time study of the seismic activity that occurred in the water injection zones for hydraulic fracturing (wastewater disposal) related to the hydraulic fracturing industry in Oklahoma, correlated the incidence of earthquakes with the water injection zones between 2006 – 2015 and 2016 – 2017(Hong Z. et al., 2018). Also, I know presented three factors causing seismicity: (i) Production water injection (disposal) wells (Kendall J. et al., 2019). (ii) fracturing water injection wells next to producing wells (Hornbach M. et al, 2015). (iii) Occurrence of poro-elastic stresses (Buijze L. et al, 2017).
Figure 1. Contamination due to failure in the production casing
A quantitative and qualitative study of the nature of geological faults would allow increasing the number of future reservoirs for exploration and drilling, due to the fact that in Peru new alternative sources are required that allow increasing the production of oil fields to achieve the development of the hydrocarbon sector (Morelo C., 2015). Peru is a country with hydrocarbon potential because it has 18 sedimentary basins with potential for hydrocarbon exploration, however, only 4 basins are explored (Ministry of Energy and Mines, 2001). Consequently, it is required to explore and develop unconventional reservoirs to increase the number of hydrocarbon reservoirs. The Muerto Formation, located in Piura, Peru, is currently being studied, which has the conditions to be the first unconventional reservoir in Peru due to its thermal maturity and its high content of total organic carbon (TOC). (Morales W. et al., 2018), this would mean a great advance for energy sustainability. Peru is an energy-dependent country because of every 100 barrels that are consumed, 75 of them are imported (Bandach A.,2018). In the year 2020 due to the COVID -19 pandemic and the abrupt drop in the price of oil, oil fields were closed because they are not economically profitable, the closure of the North- Peruvian pipeline caused a decrease of 61.2 MBPD in the month of February 2020 to 31.5 MBPD in the month of May 2020. (Yesquen S., 2020)