Near wellbore damage such as crush zone damage within perforation tunnels or skin damage caused during drilling and completion can severely restrict production rates. FloWell is a slickline deployed system which can create a dynamic underbalance at any given location within the well bore. FloWell uses Peak plugs to isolate the zone of interest and prevent unwanted stimulation of nearby zones. Situated between the plugs are the FloWell stimulation tubes that can be stacked to accommodate any given interval.
Peak introduces a new addition to its proprietary SIM System range for well remediation and flow control. FloWell is a slickline-set remedial technology capable of removing formation damage within selected downhole zones thus improving well productivity.
FloWell is designed to improve well productivity by removing certain types of formation damage (e.g. crushed zones in perforation tunnels, tenacious filter cakes and scales) in both oil and gas wells that are wireline-perforated. The condition of the near-wellbore region is critical to the production of hydrocarbons, and the perforating process is one major contributor to skin damage. The severe compressive force of perforating can reduce the permeability of the surrounding rock, which in turn reduces productivity.
Like the rest of the products within the SIM System range, FloWell is run, set and retrieved on slickline. Used in conjunction with Peak’s SIM Plug Systems to provide selective isolation of the zone to be treated, FloWell induces a sudden pressure drawdown in a wellbore, resulting in a surge of fluid inflow from the reservoir.
FloWell has been designed specifically for deployment in monobore oil and gas wells that are wireline-perforated.
All SIM System products are mechanically set, providing operational flexibility and safety. As a consequence of being run on slickline, it offers operators a cost effective and low risk intervention method to clean-up wellbore damage whilst conducting routine slickline operations.
FloWell is a dynamic underbalance system designed to improve productivity by the removal of skin and perforation damage.
FloWell is a slickline deployable system that can be used to create a dynamic underbalance across a pre-determined interval within a monobore / pseudo-monobore completion string.
The system utilises Peak’s unique field proven SIM and SIMPLUS Plug systems as a means of zonal isolation between which the FloWell System is run and activated.
Its modular design offers flexibility and enables varying lengths of sand face to be treated. The packer isolation alleviates any chance of unwanted stimulation in zones of no interest.
Testing
The primary reason for developing Flowell is to improve well productivity by removing certain types of formation damage (eg, crushed zones in perforation tunnels, tenacious filter cakes and scales).
Peak’s Flowell device consists of a number of chambers filled with air at atmospheric conditions, positioned between two Peak SIM-plug packing elements.
The relevant dimensions and capacities for a Flowell device set inside a 2-7/8” nominal (6.4 lb/ft) pipe are as follows:
The wellbore fluids are likely to consist of some or all of the following: oil, saline water and hydrocarbon gas. The isothermal compressibility of these fluids is typically in the following ranges:
- Typical Wellbore Conditions Considered;
- Bottom hole temperature 350℉;
- Bottom hole pressure 4000psi, when shut-in;
- Liquid compressibility 3.0E-06/psi(ie,water or brine).
A mathematical model has been created that describes the steady state and isothermal pressure response of the system, assuming no inflow from the reservoir. As described in the previous section, this approach should estimate the maximum drawdown likely to be seen in the wellbore.
The model allows for a mixture of gas and liquid to be present in the wellbore before the Flowell device is activated. However, the model does not consider the presence of gassaturated liquids in the wellbore.
Application of the Flowell Device in a 2-7/8in Monobore Well
The equations above have been solved for the system described in the previous section (ie, 4000 psi at 350°F). The results are shown on the chart overleaf, for the full range of possible initial gas fractions in the wellbore. The graph shows the solution the more comprehensive treatment, including both gas and liquid compressibility. If liquid compressibility is ignored (the approximate solution shown above), the results agree to within better than 0.3% over the entire range.
The results of the modelling show that Flowell device is capable of generating a substantial pressure drawdown inside the wellbore. The magnitude of the drawdown is very dependent upon the volume of any free gas present in the sealed annulus around the Flowell device.
The primary purpose of this report is not to assess the stress state of the casing induced by activating the surge tool. However, it is worth noting that maximum drawdown in the system considered in this report is far below the API collapse rating of 2-7/8in tubulars typically used in slimhole monobores (eg, being 11,170 psi for 6.4 lb/ft, 80 ksi yield pipe).
Applications
1.To remove formation damage in perforation tunnels;
2.Recover injectivity in injection wells.
Features & Benefits
1.Uses standard slickline tools and running procedures;
2.Safe – 100% mechanical, no pyrotechnics or electronics required;
3.Modular design allowing any length of zone to be treated;
4.Easily field re-dressable in remote locations;
5.Sized to pass through standard completion restrictions;
6.Standard fishing neck design for simple recovery;
7.High temperature applications up to 350℉;
8.Cost effective means of improving productivity.
FloWell is a cost effective, low risk, intervention method to clean up wellbore damage.
The FloWell deployment sequence is initiated by setting a SIM Plug at the lower end of the zone being targeted for stimulation. The required number of FloWellTM tubes are then stacked together with an upper SIM Plug set on top to achieve zonal isolation.
An activation prong is deployed to depth and downward jarring is then applied to start the surge sequence.
The FloWell is run, set and retrieved on standard slickline.
Commenting on the introduction of SIM FloWell, Tim Williams, Business Development Director for Peak Well Systems, said: “SIM FloWell has been designed specifically for deployment in monobore oil and gas wells that are wireline-perforated. We anticipate that, given the uptake of our SIM System technology by the largest multi-national operators, the SIM FloWell will also be very well received.”
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