Effective cleanup of injector wells is essential to achieve target injection rates without fracturing the rock.
In a series of recent North Sea treatments, ORCA for WBM formulations based on Acidgen™ FG3 formic acid precursor have proven highly successful for achieving effective cleanup of carbonate polymer DIF filter cake in water injector wells. Water injection into the rock matrix was achieved at below fracture pressure as required.
In contrast to older formic acid precursors, Cleansorb’s second generation formic acid precursor, Acidgen FG3, is not classified as corrosive to skin. The product is not regulated for transport by any route.
Acidgen FG3 is highly miscible in most common oilfield brines and is also denser than previously available formic acid precursors, making it easier to produce treatment fluids with a high specific gravity.
In addition, it is very low hazard and may be regarded as a “green” chemical, made from renewable resources. It breaks down to solely PLONOR products (substances considered by OSPAR to pose little or no risk to the environment).
The new formic acid precursor has now been extensively and successfully deployed in WBM damage treatments in South America, the North Sea and the Middle East. It is an innovative, safe technology that improves well productivity with minimal risk to equipment, personnel or the environment. It can be used in a wide range of downhole stimulation and completion applications in oil and gas production wells as well as water and gas injection wells.
Effective filter cake cleanup delivers increased production rates, even in long openhole horizontal sections and deviated wells.
APPLYING ACIDGEN FG3
Acidgen FG3 is dissolved in fresh water, sea water or completion brine, together with other ORCA for WBM chemicals, to produce treatment fluids for water-based mud damage removal, or acidizing of carbonate formations.
ORCA treatments may be applied in new wells using mud pumps and the drill string. In some cases, it is possible to use the treatment as gravel packing fluid. In this case the filter cake remains intact during gravel placement before being broken down.
The fluid may also be placed after gravel packing using a wash pipe. For treating wells that have already been in production, the fluid may be placed using bullheading or coiled tubing.
INNOVATIVE CLEANSORB PRODUCTS
Acidgen FG3 is one of Cleansorb’s latest innovations. Since 1994, the company has pioneered the use of in-situ acidizing in the oil & gas industry. It remains the only specialty reservoir chemistry company entirely focused on in-situ acidizing, particularly as a component of filter cake breaker systems.
Cleansorb treatments are recognized worldwide as an optimum solution in all major producing regions.
