Water Shut - Off Treatments in Oilfield by Micro and Nano Technology: A Good Way to get More Oil and Less Water.

Abstract

Abstract It has been developed a novel chemical based water shut-off technology for reducing water cut and increase crude oil production in mature fields. This technology employs polymeric gel beads (micron size range) suspendend in an organic solvent, hereinafter referred to as SMART W, which can swell selectively in contact with formation water and remain stable in contact with crude oil. Then an interconnected network of swollen particle can be generated in situ exclusively inside the water rich pattern. A proper amount of this gel can be able to plug water inflow pattern, even fracture or high permeability paths originated, while the crude oil filled fractures or paths continue to produce as before treatment. Gels beads dimensions can be properly chosen to act on water coming from fractures or high permeability paths and can be applied by means of common bullheading procedures and equipment. This is of outmost importance if wells are not able to produce in natural flow, like those that are producing by Sucker Rod Pump or other similar crude oil lifting system, then reducing water will increase crude oil production by same extent. In this way is then possible to increase estimated recoverable reserves or reduce investment cost to access to such reserves, infact water production is a major problem that affects all wells and, in some context, can cause the premature shut-in of the well itself. Finally reduction of produced water is anyway important with consequential advantages in terms of i) corrosion, ii) bacterial growth, iii) scale deposition, iv) sand production and more in general has a positive impact on oil center facilities overall treatment capacity. SMART W had been succesfully evaluated first at laboratory scale and then with several field trials in order to demonstrate the effectiveness and the significant benefits in terms of water/oil ratio. In addition, this technology has also been proven satisfactory in terms of duration of treatments effectiveness and selectivity. No any adverse effect has been expected or detected on oil center facilities. Versalis S.p.A. succeeded in scaling up the formulation of a microgel polymer to industrial level in order to have it available in industrial quantities.