Extracting oil from horizontal wells in naturally fractured carbonate reservoirs (NFR) is challenging. To properly evaluate the formation, a solution was developed that integrates key formation evaluation technologies with stimulation systems and which has proved to be effective in holistically solving such challenges.The holistic well analysis included evaluation of static data by integrating all available openhole data and special logs. To locate the most productive zones, fracture characterization was conducted using advanced interpretation techniques. Dynamic evaluation also included the analysis of measurements obtained using a formation tester. An integrated technical solution included a proper matrix stimulation design that considered all these data to reduce formation damage and connect the fracture networks.This study successfully confirmed the presence of hydrocarbons in the T field in southern Mexico for the first time. Production not only exceeded expectations, but also added reserves to this new exploration area, aiding in the development of the Upper Cretaceous formation referred to locally as the KM.

To date, the art of effective openhole, horizontal well fracturing is not well defined. Difficulties in regional sealing hamper the fracturing task and results can be suspect. Without proper isolation methods, the use of openhole, horizontal well fracturing is limited. During many fracturing processes, fracture or acid placement often occurs where fluid first contacts the borehole, often at the heel of the well. A new method is now available that combines hydra-jetting and fracturing techniques. By using this new method, operators can position a jetting tool at the exact point where the fracture is required, without using sealing elements. Unlike other techniques, this new method allows operators to place multiple fractures in the same well; these fractures can be spaced evenly or unevenly as prescribed by the fracture-design program. Large-sized fractures can be placed with this method as well. This technique was applied in a low-permeability environment in a horizontal, openhole completion. Treatment design proved simple, but unique to the job, to which success is attributed. In addition to tailoring a design for such treatment, reservoirmonitoring methods were applied to help measure the effectiveness of the overall stimulation program. Surface tiltmeter technology was used to map the hydraulic fractures. Mapping results indicated that induced fractures were placed in the area of interest, a well-documented difficult task on an openhole completion. This paper discusses the basic principles of horizontal hydrajet fracturing on an openhole completion, observes the operational advantages of the technique, and highlights the significance of matching the right application to the right environment for treatment success.