The Development of a Revolutionary Scale-Control Product for the Control of Near-Well Bore Sulfate Scale within Production Wells by the Treatment of Injection Seawater

Abstract

The formation of sulfate scales arising from the injection of seawater into hydrocarbon-bearing formations for pressure maintenance and secondary oil recovery has been a significant problem in many onshore/offshore operations. To address this, batch scale inhibitor squeeze treatments, scale removal, and modification of the injection brine (sulfate removal, produced water injection, aquifer water injection) have been applied with varying degrees of success. The development of deepwater projects, where conventional scale control technology may be uneconomic for the control of mineral scale, has required a re-evaluation of the methods of scale inhibitor deployment. For the past five years, BP Exploration has been developing a novel approach to the application of scale inhibitors with the objective of eliminating the requirement for both active scale inhibitor squeezing and scale removal operations. This has been achieved by the development of nano-sized, controlled release, solid scale inhibitor particles that can be added to the injection water such that the particles pass through the formation and release the scale inhibitor into the fluids near the production wells. The principle of solid particle transport in porous media is demonstrated using core flooding tests and reservoir modelling. This confirms that solid particle transport is possible and that minimum retardation relative to the injected brine can be achieved. Static and dynamic release characteristics of the scale inhibitor formulations evaluated to date will be presented. The factors to be considered in the commercial manufacture and initial field trial results will also be presented together with the economic justification for this type of scale control process. This technology offers a revolutionary scale control process that could eliminate the need for sulfate-reduction plants whilst still providing effective scale control within the reservoir and near-wellbore region for deep water developments.

The Reservoir Injury Rules of Water Injection to an Ultralow Permeability Reservoir: Experimental Research Based on Core-NMR and Microfluidic Technology

“…It can be observed that with the prolongation of displacement time, the axial hydrogen signal intensity of both cores gradually decreases, indicating that the damage to the cores by injected water increases with the prolongation of displacement time. Additionally, another important feature can be observed: at the location of the front of the two cores, the intensity of the hydrogen signal is significantly enhanced in the late stage of flooding, indicating that in the late stage, the uncemented scale particles as well as the weakly cemented clay particles that were washed out by the water were carried by the water flow and transported along the throat to the back of the cores, 41 and the transportation of the solid particles is shown in Figure 7. The water phase occupies the space at the front that has been washed out, resulting in the hydrogen signal at the front is then significantly enhanced.…”

Review of Nanotechnology Impacts on Oilfield Scale Management

“…British Petroleum (BP) Exploration were the first to report the development of a microemulsion system in oilfield scale inhibition applications. They synthesized microemulsified SIs in order to increase the SI squeeze lifetimes. − …”