The necessity for hydrocarbon-producing countries to increase their reserves has led to companies exploring the deposits available in source rocks that might be over-pressured and thus, strict rules are required for their development. Overpressure, which may result in wellbore stability problems, could result from several causes such as mechanical effects, dynamic transfer, chemical stress, thermal stress, among others, in which undercompaction is frequently the main cause, generated when the sediment deposition velocity exceeds the fluid ejection rate.The expansion of fluids generated by thermal stresses and the reduction of porosity caused by chemical stresses may be among the other causes of overpressure in shales. The new methodology presented in this paper makes it possible to determine the pressure due to thermal stresses caused by the cracking of kerogen and oil in shales. In addition, petrophysical and geochemical models are considered in order to precisely ascertain the increase in pore pressure due to temperature andfluid expansion. An increase of 20% in pressure is seen when compared with undercompaction. As a result of this methodology, the mud window was optimized and the hydrocarbons, generated under subsurface the conditions (pressure, temperature) analyzed, were quantified.

The Cesar´s Department has presented historically problems in terms of availability energy, which has hindered the implementation and continuity of some projects. One of the alternatives solutions focuses on the use of solar energy in this area, considering that the highest daily average brightness values are in the Caribbean region and the Orinoquia. For this reason, the Municipality of González, in the Cesar Department, promoted the construction of the first aqueduct in Colombia that operates only with hydraulic and solar energy, which ensures continuity in the drinking water service, and the contribution with the reduction of CO2 emissions at the atmosphere , In order to minimized the use of fuel for this operation. In support of the above investigation, the object of the present project has two main ideas; the first one is estimate the radiation potential in the municipality of González and the second one is establish the dimensions of the photovoltaic solar system to take advantage of this kind of energy. The mathematical model selected, is an empirical one proposed by Bristow-Campbell, based on the availability of information, and the match presented in previous studies , in which was analized secondary information, coming from the Aguas Claras Airport weather station, and the information available on the POWER page, that is a set of solar and meteorological data from NASA’s researchs for renewable energy. For the evaluation of the photovoltaic solar system, it was used a methodology based on the radiation potential available in the area, the energy requirement in the operation of the drinking water treatment plant, the administrative and laboratory facilities of the municipal aqueduct and the measure that were used of the generation, accumulation and investment regulator subsystem. It was conclude that the radiation potential for the Municipality of González, is estimated in a range between (4.5 and 6) KWH/m2/day, and that value is enough to meet th average, as well as the measurement proposed, have the capacity to supply electricity in the operation of the potable water treatment plant, the administrative and laboratory facilities of the aqueduct.

Sanding during hydrocarbon production is a critical problem in many fields around the world, in Colombia it is common in fields of the Magdalena Middle Valley, which entails high costs for operating companies due to continue cleaning and damaged equipment interventions, as well as, decrease in production. That is why predicting conditions under which sanding is being generated is an important component of field management. In this work a methodology has been applied that integrates into a diagnostic diagram: production information, sand production interventions, fluids, completion and formations, correlating the most critical sanding zones with the behavior of rock destabilizing variables such as: rates and fluid type (drag forces), liquid levels (drawdown impact) and rock competence. From this analysis, it is possible to recognize the areas that are most sensitive to producing sand and the operating conditions that sharpen the scenario. For the field under study, Formation A was identified as the most prone to sanding due to the low resistance and degree of consolidation of its rocks, as well as the high water cuts and pressure depletion of the reservoir. Similarly, it was possible to identify drawdown management as a sanding-prevention measure, and the installation of Gravelpack as an exclusion method. As a result of the state of the art carried out in support of this research, it was found that existing methodologies focus on estimating the stresses under which the rock fails and therefore produces sanding but they do not focus on analyzing the root cause and conditions that can cause sand production in the first place, which is important to understand the behavior of the rock under different stresses.

ResumenDurante una perforación es de gran importancia tener una ventana de estabilidad lo más precisa posible para evitar problemas como colapso del pozo, influjos, pérdidas de circulación o de filtrado, entre otros. Aunque la geomecánica permite determinar una densidad óptima, en la realidad pueden existir formaciones permeables por las cuales pueden ocurrir pérdidas de filtrado considerables lo cual aumenta los costos. En literatura existe un modelo matemático que proviene de la ley de continuidad, una ecuación de estado y una ecuación de flujo (Darcy) el cual es utilizado en análisis de pruebas de presión, analizando la presión necesaria para tener flujo de la formación hacia el pozo. El objetivo de esta investigación es demostrar que este modelo se puede implementar para estimar la presión permitida del lodo durante la perforación y controlar el filtrado del este fluido hacia la formación para de esta forma, adicionar una nueva curva a la ventana de estabilidad. Para lograr tal objetivo se utilizaron modelos y correlaciones y se dio un estimado de las propiedades de la formación en función de la profundidad y con un caudal máximo permitido de pérdidas de filtrado, se determinó la presión adicional a la presión de formación con la cual se puede perforar sin presentar grandes pérdidas de filtrado disminuyendo los costos. Finalmente, se hizo un análisis de sensibilidad concluyendo que la permeabilidad y la viscosidad, son las variables más importantes del modelo. AbstractDuring a drilling, it is very important to have a stability window as accurate as possible to avoid problems such as collapse of the well, loss of circulation or filtration, among others. Although geomechanics makes it possible to determine an optimum density, in reality there may be permeable formations whereby considerable filtration losses can occur which increases costs and NPT. In literature there is a mathematical model that comes from the law of continuity, a state equation and a flow equation (Darcy) which is used in pressure test analysis, analyzing the pressure needed to have flow from the formation to the well . The objective of this research is to demonstrate that this model can be implemented to estimate the allowed pressure of the sludge during the drilling and to control the filtration of this fluid towards the formation in order to add a new curve to the stability window. To achieve this objective, models and correlations were used and an estimate of the properties of the formation as a function of depth and with a maximum allowed filtration loss rate was determined, the additional pressure was determined with which It can perforate without presenting great loss of filtration reducing costs. Finally, a sensitivity analysis was made concluding that permeability and viscosity are the most important variables of the model.

El gas puede estar presente en la roca generadora, ya sea como gas libre en el medio poroso, gas libre en las fracturas naturales o gas que se encuentra adsorbido, el cual puede llegar a representar hasta el 85% del volumen total presente en el yacimiento. Diferentes cuestionamientos han sido generados por los profesionales de la industria de los hidrocarburos acerca de si todos los parámetros necesarios son considerados en la cuantificación del volumen de gas original in situ, con el fin de mitigar la incertidumbre en su estimación. El objetivo de esta investigación es estudiar los principales métodos y correlaciones empleados para cuantificar el gas adsorbido por la roca, para finalmente estimar el gas total. Para lo anterior, se estudiaron múltiples modelos de adsorción con información de la literatura, con el fin de determinar cuáles modelos presentaban menor desviación, con respecto a los datos de laboratorio. Así mismo, usando las características de la Formación La Luna en Colombia, se propone una analogía con el fin de estimar las posibles reservas de esta formación. Los resultados demostraron que los modelos con mayor número de parámetros involucrados presentan mejor ajuste con los datos de laboratorio, sin embargo, modelos como el de Langmuir de tres parámetros o el de Jovanović se acercaron en gran medida a los valores reales. Lo anterior garantiza un menor error en el cálculo del gas total.