Published: 11/01/2011
Published: 11/01/2011
Due to the stratigraphic profile of the shale and sandstone lenses in Colombia’s Valle Medio del Magdalena, specifically in the Nutria and Tesoro fields, conventional fracturing treatments are performed by grouping several formations together. However, stimulation treatments under these conditions do not guarantee that the fracture connects all the different zones.
In an attempt to connect every zone, the operator pumped massive conventional fracturing jobs. However, a production logging tool (PLT) run showed no fracture conductivity due to swelling clays and proppant settling by gravitational decantation.
After the fracturing treatment, the wells produced until a drop in production was observed. Then, a new set of perforations was opened in an attempt to connect the fractures in the lower zones. This technique showed a temporary increase in production, followed by a quick decline. This decline in production was possibly due to clay swelling, as the massive conventional fracturing jobs contacted undesirable zones.
Because the conventional stimulation technique did not provide the expected production and involved additional well interventions, the client looked for new technological alternatives via its multidisciplinary group (reservoir, production, and operations). The operator chose to use the AbrasiFRAC service.
The AbrasiFRAC service perforates and stimulates multiple well intervals in a single field operation, providing reservoir connectivity in less time. It eliminates the need for packers and frac string, which had presented numerous problems in previous treatments.
The AbrasiFRAC service offers a single, simple, rigless completion from shooting to well cleanout. The shooting (jetting), breakdown, and fracturing treatment are performed in hours instead of days. The application of the AbrasiFRAC service also frees up resources, such as workover rigs, for other jobs.
The service enables accurate placement of fracturing treatments for individual zones in reservoirs with shale and sandstone lenses. The AbrasiFRAC technique also minimizes near-wellbore pressure drop from the wellbore to the reservoir, which reduces the frequency of near-wellbore screenouts.
The use of coiled tubing (CT) for the opening of channels before the fracturing treatment in the zones of interest ensured a high degree of selectivity during the treatment and ensured that the client would have a CT unit available for the cleanout after the fracturing treatment.
The AbrasiFRAC service reduced operational time by 35%, cut general completion costs by up to 10%, and reduced horsepower required at the wellsite by 50%. With a workover rig on location, it would have taken 11.5 days to execute the same treatment. This rigless solution took 7.5 days to execute, saving 4 operational days.
The availability of the workover rig on another well provided an additional gain of 350 bbl/d of oil for the client. Additionally, after 6 months of production, the well treated with the AbrasiFRAC technique met the client’s expectations and has not shown a decline in production.
As a result of using the AbrasiFRAC service, the client had the ability to use their workover unit to perform some maintenance jobs in other wells. The AbrasiFRAC technology is now planned to be used in the next four wells on the new drilling campaign in Tibu, Norte de Santander, Colombia.
Challenge: Maximize reservoir contact by fracturing multiple zones independently in a single well intervention.
Solution: Use AbrasiFRAC abrasive perforating and fracturing service.
Results: Cut operational time 35%, reduced general completion costs by up to 10%, decreased hydraulic horsepower 50%, and eliminated packers and frac string.
