This paper demonstrates how innovative data acquisition, phased planning and world class placement of filler material in a short circuit lead to a successful water shut-off restoring 477 m3/day (3,000 BOPD).

Hess operates the South Arne Field located offshore Denmark. Two flank horizontal wells, a producer and a water injector, started short-circuiting water via an abandoned sidetrack. High pressure (517 barg) water from the injector flowed directly into the producer (172 barg) killing the oil production.

The wells’ horizontal length is 3 km and is completed with a cemented liner. The liners are subdivided into 17 zones with production/injection tubing, iso-packers and sliding sleeve doors. Each zone has been stimulated with acid fractures.

The vital part of the data acquisition was multiple tracer tests from different zones at different production and injection ratios, which increased the tracer recovery from 15% to 100%. In addition, tracer data revealed transit time, sidetrack volume and number of paths; all crucial information for a successful water shut-off. A gel mimic test was performed to account for differences in rheology.

Pressure and temperature logging tools in the wells provided the pressure and temperature gradient along the sidetrack, which was crucial data for placement of the temperature sensitive filler material.

The decision was to approach the challenge in three phases; firstly, data acquisition; secondly, interpretation of data, filler material laboratory tests, design of job; thirdly, implementation of the water shut-off. This proved to be advantageous as it allowed time for appropriate adjustment and planning of the complex setup.

The 19 m3 (120 barrels) of filler material was mixed on the platform and pumped into the injection well tubing while producing from the production well at controlled condition with one optimal sliding sleeve door open in each well and an optimal production/injection ratio The temperature of the filler material increased as it travelled to its final destination in the sidetrack leaving a 450 m (1475 ft) solid isolation plug.

One year after the water shut-off, oil production has increased from 0 to 477 m3/day (3,000 BOPD) saving an expensive and challenging re-drill.

This project underlines the importance of spending time and money, upfront, on innovative acquisition and planning to increase a project's chance of success.

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