Cleaning oil wells

Oil drilling is one of the most important sources of energy in the world. It enables the exploitation of oil which is later used for various purposes, from fuel production to plastic production. However, during the operation of wells, their flow rate decreases for various reasons. One of the possible causes is contamination of the bottomhole zone of wells. In order to solve this problem, our technology “Vibration-resonance cleaning of the bottomhole zone of wells” was created.

How it works

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Introduction

– Application of resonant frequency can increase filtration rates as much as 3 times
– Past technologies did not create resonant frequencies
– The method and technology creates resonant frequency of regions of a reservoir that require stimulation – skin removal
– Past technologies could damage production by stimulation of intervals that should not be stimulated
– The method and technology precisely stimulates the target interval.

The method consists of:

– Measuring or calculating the resonant frequency bandwidth of formation
– Calculating the design parameters of wave generator
– Wave generator is attached to the end of either standard production tubing or coiled tubing
– Tubing is lowered into wellbore such that the wave generator is placed at the target stimulation interval
– Circulation of wellbore fluid is started at specific rate and pressure

Treatment Scheme of Near Well Zone

Near zone treatment is carried out in the regime of circulation as follows:

Standard separation tank 7 – Pump 6 – Tubing 1 – Wave Generator Device 4 – Casing 2 – Standard separation tank 7 during 4-8 hours depending on Size of treatment zone.

Duration of treatment for horizontal wells depends on the length of its horizontal part. In case the use of Coiled Tubing, the pulling out of tubing is eliminated and, for instance, it’s possible to provide the treatment of active gas-lift wells, i.e. without shutting down the ones. Such Treatments were used for gas-lift wells in Prudhoe Bay oil field (Alaska, USA) and on the platform “Ula” in North Sea.

1- 2 7/8” Tubing, 2 – Casing, 3 –XO 2 7/8”-2 3/8”, 4 –Wave Generator Device, 5 – SSW, 6 – Pump capable provide 2.8-3.2 Bbls/min (26-30 m³/hour) flow rate under 2800-3000 psi (19.5-21.9 MPa) pressure, 7 – Standard Separation Tank (V = 30-40 m³), 8 – valves, 9 – Pressure Gauge, 10 – Sealing Connector between tubing and high pressure hose, 11- High Pressure Hose.

Advantages of our technology

1.1 Most existing near wellbore zone treatment technologies may have the opposite effect – a decrease in oil production with an overall increase in fluid production at a given well as a result of the cleaning of the highly-permeable sublayer and thus may cause the disconnection of less permeable oil-containing sublayer out of operation.

Vibration-resonance technology provides the cleaning of the contaminated sublayer in the resonance mode, allowing to remove the skin factor on this sublayer, without causing additional cleaning of the highly-permeable sublayer.

1.2 Accessibility and Ease of Use.

Standard oil equipment (rig), commonly used in the oil field workovers and the corresponding rig crew are used for this technology.

1.3 High efficiency.

The average increase of oil production during over the more than 30 years of implementation of this technology accounted for 40%, and the increase of injection rate for injection wells was 16%. Before the treatment, the well produced 12 cubic meters of oil per day, and after the treatment, it began to produce 39 cubic meters! Аn increase of 270%! Moreover, in some cases (MM-595 Well at Marmul field (Oman) (Slide 16 Presentation in Russian) after cleaning near well zone the increase of the oil production accounted for 325%, and for F42 well (Slide 19 Presentation in Russian) at Prudhoe Bay field (Alaska) before the treatment, the well produced 94 bars per day, and after the treatment, 413 bars. This is 319% the increase of the oil production!

These graphs can also be posted on.

1.4. Significant increase in the maintenance period during well operation.

1.5 Continuous improvement of the equipment being used. Unique equipment is designed and manufactured for each specific well.

1.6 Applicability of technology. The Vibration-resonance technology works equally well in vertical, inclined or horizontal wells, being on onshore or offshore.

1.7 For Vibration-resonance technology there are practically no limits on producing depth.

1.8 In gas lift wells the use of Coiled Tubing is processed without pulling out of tubing.

1.9 Injection wells can be stimulated permanently for a long (1.5-2 months) time by using existing injection rate for particular well.

2.0 Environmentally friendly. Vibration-resonance technology is an environmentally friendly technology. Fresh water is used as a working fluid.

Results of treatment of F42 Well in Prudhoe Bay oil field (Alasks, USA)

F-42 increased oil production from 94BOPD to 413 BOPD

Results of treatment of Horizontal Well MM-555 in Marmul oil field (Oman)

MM-595 increased oil production from 12 to 39 m3/day

Environmental aspects

Oil exploitation can be very harmful to the environment if environmental aspects are not taken into account. Water, air, and soil pollution are just some of the problems that can arise. Therefore, various measures are taken to reduce the negative impact on the environment. For example, barriers are set up to prevent the spread of pollution, advanced technologies are used for wastewater treatment, and so on.

Safety

Oil exploitation is dangerous to the health of workers, and catastrophic consequences can occur for the environment. Therefore, various measures are taken to reduce risks and increase the safety of workers and the environment. For example, workers are trained, early warning systems are installed, and safety regulations are enforced.