Increased Oil Production And Recovery
A major challenge in oil production is to maximize the total oil recovery from the reservoir. Most wells and fields only recover and produce a limited portion of the actual oil in a given reservoir before the well/field is shut down.
Two factors are of particular importance in order to improve production and recovery from a reservoir; obtaining maximum reservoir contact and preventing negative effects of gas and/or water breakthrough. Good reservoir contact is achieved by drilling long horizontal and/or multi-lateral wells. However, long wells give pressure variations between the toe and heel section of the well. This creates non-uniform influx along the well and results in an early breakthrough in the heel section. Permeability differences and fractures/heterogeneities along the well will also result in early breakthrough in some parts of the well. Well completions with Inflow Control Device (ICD) consists of a number of ICDs disposed at regular intervals along its entire length. The ICDs causes a flow restriction of the fluid flowing from the reservoir and into the well, and will make the inflow profile more uniform. The ICDs are ports having a fixed flow area. The result is a more uniform and will delay the gas/water breakthrough, but cannot control the gas/water breakthrough issue. Autonomous Inflow Control Devices (AICD) is devices that can adjust the choking of the fluids depending on which phase being produced. They are placed along the well in the same way as the ICDs.
Statoil developed the autonomous RCP, Mathiesen et al. (2011). The AICD restricts the gas compared to the oil production, and these wells have lower gas/oil ratio (GOR) development than wells completed with conventional ICDs. However, they will still have excessive gas production and the wells have to be choked. The novel and patented Autonomous Inflow Control Valve (AICV®) is an improved AICD that can shut-off the gas and water completely. These AICV® do not choke the oil production significantly, and can stop gas and water completely at a breakthrough point.
The AICV® closes autonomously and completely shut-off the unwanted fluid production at breakthroughs locally in the well. At the same time oil production will continue from the other inflow zones along the well, ensuring optimum oil production and recovery.
The AICV® is completely self-regulating, and does not require any form of control, electronics or connection to the surface. This provides operators with significantly more efficient production and increased recovery. AICV® technology enables opportunities to drill longer wells and achieve maximum reservoir contact and importantly achieve 'production conformance' within each well.
The technology makes it possible to maximize well production far more efficiently than ever before. The AICV® eliminates the gas and water breakthrough problems, and supports 'Making Better Wells'.