Agenda

Dealing with produced water in an offshore environment can be challenging, due to the fact certain requirements must be met to handle the large volume of produced water. On offshore installations, whether fixed or floating facilities, there are weight and space limitations for adding new equipment to handle the increase in the produced water rate. In this scenario, it can be very challenging to handle the water for both discharge and reinjection options. New technologies, processes, and chemicals can help but in some cases there are limitation, in terms of cost implications and to meet the environmental regulations. In more critical cases, the specification of produced water are becoming more stringent to achieve. Hence there are opportunities to improve current approach, strategy and understanding on how to handle the product water in an offshore environment.

Flow Assurance, originally coined by Petrobras as “Garantia do Escoamento” represents the application of successful and economical processes so that the reservoir fluids can be delivered optimally from the pore space to the final point of discharge (sale, treatment or disposal). The well and the wellbore vicinity are the connection between these two end points. And this connection, the well, can be severely compromised with the presence of acids, scales, solids production, corrosion, etc. In the session we intend to highlight the enormous impact that the condition of the well has in the proper management of water in the case of production and injection.

Water treatments such as mechanical/physical, chemical, and biological methods are always a delicate issue in any field operation. Technology and new chemicals have shown alternative solutions both for separation and general water handling. This can be a determinant factor for well injectivity and injection/production facilities.

However, it is well documented that for EOR processes water quality can become critical. Polymer flood or thermal process usually requires enhanced efforts in water treatment to assure low-level of impurities and even control other variables like H2S, O2, Fe, Mg, Ca. To achieve these objectives operations need to be careful when solving separation issues selecting compatible chemicals to assure downstream EOR efficiency.

These types of applications like bright-water, low-sal, HPAM, and thermal processes require rethinking water management processes. These new approaches can vary for different cases and require tailor-made solutions for every operation and company. This session will cover all approaches to tackle these issues aiming to optimize project performance and share and discuss pros and cons by field examples.

As the environmental regulations for water discharge are becoming more and more severe, produced water re-injection (PWRI) is now recognized as an important issue with respect to environmental protection and profitability and allows handling the even larger volumes of produced water. Therefore, most of the produced water has to be re-injected either in a suitable formation for disposal or in the producing formation for pressure maintenance, water flooding and chemical EOR purposes. However, great uncertainties remain about the consequences of produced water re-injection. Among these are the important issues related to the formation damage and associated injectivity decline. Understanding the injectivity loss mechanisms during PWRI and evaluating the impact of such injectivity loss on performances and costs are thus important research needs.

Injection water quality is a critical factor that impacts well injectivity.  Throughout the life of a well maintaining acceptable injectivity can be challenging and lessons learned sharing can support industry learning .   This session will provide case studies for water treatment and injection strategies that support stabilizing and / or improving well performance including but not limited to: water technology treatment solutions, well stimulation alternatives, and out of zone injection scenarios.

Discharge of produced water is strictly regulated. Worldwide for offshore around 70% of produced water is discharged. For onshore, over 80% of the produced water is reinjected with the rest being either reused and or discharged. Environmental regulations and requirements for produced water discharge have been evolving. In the past for offshore the focus has been on the dispersed oil which is used as a surrogate for measuring the discharged water quality. In recent years, however, risk based approach in addition to measuring oil content has been implemented in places like the North Sea. For onshore environmental regulations and requirements are much more stricter, here oil content is only one of many parameters that are required to be measured and meet with standards. This session will discuss current practices, trends and also challenges in implementing the risk based approach and the inclusion of water soluble organics for reporting.

Mature fields have the common challenge of extending economic viability. Optimizing OPEX is crucial to achieve goals, and water management always has a direct impact on asset expenditures. The goal of this session is to exchange ideas around how the increase in water rates affects the production life of mature fields. Focus will be put in subsurface optimization issues together with an integrated asset management approach. Topics such as water conformance, water shut-off, sustainability and water disposal will be analyzed and discussed.

The efficiency of water injection processes is heavily dependent on the integrity of the systems and equipment that make it viable. Damage in the well region, whether internal or at the well-reservoir interface, impairs injectivity and requires special resources for remediation. The purpose of this session is to discuss the influence of geomechanical conditions, equipment integrity, injectivity restoration as a result of injecting water into the reservoir well system. We will also address prevention, mitigation and remediation of any damage that may occur due to water injection, and the consequences on oil production.

Presentation title: Injectivity and Water Quality

Produced water is conventionally treated through different mechanical / physical, chemical, and biological methods. In order to meet water quality requirements for re-injection, discharge and / or re-use, emphases may be placed on optimization of current treatment processes and the use of combined treatment technologies. The use of on line oil-in-water monitors could also be very helpful to provide continuous information needed for process optimization and may play a major role in the management of produced water in the future. Indeed, in a context of environmental concern, of water-stressed countries, there is a need for reliable, accurate monitoring to measure the quality of the treated produced water either for implementation of re-injection into a formation or discharge to the environment. In recent years, the use of online oil-in-water analyzers for produced water discharge reporting has also gained momentum. The objective of this session is to discuss trends with new treatment and monitoring technologies as well as practices.

Waterflooding is commonly performed in oilfield wells for pressure support and increased oil production.  Different sources of injection water can be used for waterflooding, including aquifer water, seawater or produced water. Each of these water sources contain particulates (solid particles, oil&grease, biofilm) which can result in filter cake formation at the formation face or inside the rock surface.  The properties of the filter cake can negatively impact injectivity and promote fracture propagation.  It is critical to treat injection water to an appropriate injection water specification to achieve sustainable injectivity and maintain sub-surface integrity.  The trade-offs between water treatment and well workover costs versus decline in well injectivity and waterflood performance must be evaluated in developing a successful injection water treatment strategy. The purpose of this session is to share experiences and projects to improve the quality of injected water and that are feasible to be implemented in production facilities.