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Since the inclusion of Micro Seismic technologies in the Barnett Shale, this technology has become one of the most powerful and used tools to monitor the behavior of reservoirs exposed to hydraulic fracturing with non-permanent arrays and also, to detect changes due to injection/production of fluids during long periods of time using permanent arrays. This paper focus its efforts in non-permanent arrays, which require the use of high resolution seismic tools deployed in the well and anchored to the casing walls to detect micro seismic events produced by induced movement in un-deformed rock or along pre-existing fractures which is in response to the interaction between natural stress directions and equilibriums and those that are being forced on the deformations through stimulation or injection. This paper will present results from the first micro seismic job done in Colombian history, which was performed in December 2010. The results obtained with the implementation of this technology want to provide an image of the zones affected with the injection of fluids, which will allow the operating company to define drainage areas and optimize the location and development of new wells in the field, optimize perforating spacing and location, analyze the containment of the fracture to the interest zone and avoid the migration or the rupture into undesired zones like aquifers, it will also help define optimal injection rates and proppant concentrations. After having a better knowledge of the fracture behavior, stress distribution and production levels, one can think in re-defining drilling strategies and to think the feasibility of highly deviated to horizontal wells; these kinds of decisions had been taken by companies that used micro seismic and were translated in millions of dollars in savings. One of the most notorious examples is the Barnett - Shale, where they moved from vertical wells to a big majority of horizontal wells, which boost the production rates and transformed this field in one of the biggest gas producers in USA; similar steps are being followed in the Marcellus shale and the Haynesville shale in USA, as well as fields in Canada, and India just to mention some. This paper center is based on results obtained from the first borehole micro-seismic job done in Colombia and will present the conclusions obtained from combining results from different services ran in the well Morpho – 1. Combining the analysis of pressure curves with micro seismic gives us a great idea of how the different fracture types can be observed and also, will help fracture designing teams to better understand and determine the best way to treat rocks. |
