Abstract
The important role of optimized injection wells has been recognized as a crucial element for optimum field development and enhancing oilfield recovery factors. The functionality of most applied technologies to provide optimum injection conformance has been limited as the properties of injection wells are continuously changing. This paper will present an overview of oilfield production data for using outflow autonomous devices and demonstrate their benefit in various well injection applications by optimizing the well injectivity.
The devices have been installed worldwide including in the Middle East, Norway, North America and China. Like other flow control devices, this autonomous device was installed in several zones in wells and has two operating conditions, one as a conventional flow control device, and two, as a barrier when the flowrate through the valve exceeds a designed limit. At the second flow condition, the denied fluid to that specific zone will be distributed among the neighboring zones. This prevents excessive fluid injection into the thief/fracture zones and maintains a balanced fluid distribution across the full targeted injection zone.
This paper describes the completion design workflow and field data including injection logging tool (ILT) and DTS and step-rate and injectivity test data when available for the cases.
The field results have proven the success of autonomous outflow control devices both in terms of achieving the target injection profile and controlling the thief zones. The objectives of installations include controlling faults, natural and thermal fractures, and high perm zones for injection of water, gas and polymer in both carbonate and sandstone reservoirs. For example, in one well the production logging results from data post and before installation confirmed that the flow control devices were successful in controlling the water injection into the suspected thief zones by 42%. Another example in polymer injection well supported by Distributed Temperature Sensor (DTS) data as well as other surveillance data, it was confirmed that 93% of the anticipated conformance has been achieved and the water cut from the oil producers nearby drastically dropped resulting in less production of unwanted fluid and therefore more sustainable oil production.
The paper will provide an elaborate showcase reviewing field data for deployment of autonomous flow control devices in injection wells and evaluate the resulting enhanced well injectivity performance and hence overall field development efficiency. The outflow control device enables operators to deliver optimum water, polymer, acid and gas injection techniques resulting in more sustainable production while avoiding costly and often complex well interventions.
