The identification of reservoir analogues if often an important step in planning the development of a new play, particularly when it poses difficult technical challenges or when appraisal information is limited. One of the strengths of an E&P company with a large and diverse portfolio is its potential to utilize a broad base of knowledge gained from past experience to aid in future development and decision-making. A critical enabler in being able to leverage this knowledge effectively is the ability to access relevant information quickly and efficiently. This paper presents a new approach to identifying analogues systematically through the novel application of an artificial intelligence technique called case-based reasoning. The key lies in characterising each reservoir by a set of attributes which describe the reservoir and can be used to differentiate it from other reservoirs. Case-based reasoning is then applied to search for reservoirs which are similar (i.e. are potentially good analogues), but that do not necessarily match up exactly on any individual attribute. Further, this method quantifies the degree of similarity and permits users to focus their search on any specified set of reservoir attributes. These characteristics differentiate this method from others currently in use. The implementation of this method to create a versatile knowledge sharing tool, called the "Smart Reservoir Prospector", will be described. Recently developed artificial intelligence technology incorporating case-based reasoning algorithms within a flexible java-based architecture has been applied. The result is a web-based system that permits users in any Shell operating unit to search through thousands of reservoirs in milli-seconds to locate reservoir analogues, and then to access additional detailed information about the reservoirs of interest. The application of this tool within Shell to address important business issues, including scope for recovery and reserves justification, recovery factor benchmarking, and reservoir knowledge sharing, will be discussed. Introduction This article describes the origin and development of a unique knowledge sharing tool for locating reservoir analogues and sharing associated best practices. The tool, called the Smart Reservoir Prospector (SRP), is accessible globally within Shell. Also discussed are the underlying business drivers and the benefits of using reservoir analogues to aid in exploration and production activities. Finally, a vision for the further development and embedment of the SRP within Shell EP's knowledge sharing communities is presented. The SRP is a reservoir knowledge sharing system with an intelligent "fuzzy logic" search facility. Its main purpose is to locate reservoir analogues in a systematic, reliable, and efficient way. This contrasts with the traditional hit-or-miss approaches such as searching through reports or relying on the individual experiences of colleagues. These approaches are generally biased towards assessing similarity on a few attributes only, and compare reservoirs on a one to one basis. The SRP assesses similarity on the basis of a broad set of attributes and compares multiple reservoirs simultaneously.

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This paper describes the operational planning and process safety due diligence performed to ensure safe and successful operations in the world's first deepwater propellant perforation in a carbonate reservoir. The Malampaya gas field in the Philippines is a depleted carbonate reservoir with five subsea development wells. The Malampaya Phase 2 Project that concluded in Q2 2013 involved drilling two new infill wells MA-11 and MA-12. Given the uncertainty in prognosis (Carbonate K-Phi) and the greater risk of not securing wells with high deliverability as per the well objectives, it was decided to use some form of near wellbore stimulation to bypass the near well bore damage zone caused by cement losses and cuttings lost to the formation while drilling the 300 m reservoir section. Propellant perforation technology solution was selected based on optimization of rig time, ineffectiveness of acid jobs in a karstified, fractured carbonate and process safety considerations of acid handling on a dynamically positioned rig. 200 m reservoir section was perforated safely and successfully with 3–3/8″ propellant perforation gun with 30% propellant loading on a 2″ coiled tubing in each of these two subsea wells. A standard 6 SPF shot density and 60 degree phasing was adopted with deep penetrating charges to bypass the damage zone suspected from drilling and cementing losses in this depleted carbonate. Both the wells delivered finally in excess of 100 MMscf/day during the well test on the rig as expected. This paper outlines the expected vs. actual well performance; process safety due diligence with an elaborate modeling focus on the worst case scenario (i.e. no cement behind the 7″ liner). Static and dynamic coil modeling results are shared along with an overview of the transient modeling conducted to optimize the final perforation interval on both the wells based on the actual lithology information.

There has been a tremendous growth in the number of high-angle and horizontal wells in the past decade. Coupled with the increase in water cut from various brownfield environments, these high angle wells present us with complex reservoir and production management challenges. Fit for purpose production logging technology is helping to provide a better understanding of fluid movement, enabling higher confidence decision making leading to successful interventions. Production logging in high angle and horizontal wells that produce mixtures of fluid phases is challenging because of the associated complex flow regimes that radically change the physics and technology of measurement. Depending on the borehole deviation, the velocity and fluid holdup of different phases can change dramatically for a given flow rate. We present examples that encompass various reservoir management objectives, well optimization and flow profiling. Surveillance logs were acquired in these wells to obtain key inputs for production optimisation, identifying bypassed oil and evaluating potential for additional perforations. Where necessary, production logs were integrated with pulsed neutron capture and spectroscopy measurements to enhance our understanding. In one of the examples, a compact integrated production logging tool comprising an array of spinners and holdup probes was conveyed with tractor in a horizontal well. Besides conveyance in this horizontal well, the challenge involved detecting minor oil entries in a very high water cut scenario. Two examples relate to the effective use of pulsed neutron spectroscopy measurements reservoirs. Finally one of the examples involves oxygen activation for positive identification of water movement behind pipe. Creating value through surveillance is the common thread that binds these well intervention examples together. Introduction North Sea oil and gas production from mature basins face some particular challenges against a backdrop of production from platform and subsea wells in a challenging offshore environment. These offshore field developments often consist of long horizontal wells with subsea completions, resulting in a high cost of well interventions and technical challenges in the conveyance of logging tools. The importance of surveillance for field management and further brownfield development cannot be underestimated, even though the ultimate benefits are not always apparent in advance. These benefits include, for example, optimizing production, reducing watercut, improving well performance, optimizing water injection and sweep efficiency, and identifying unswept areas of the field to target with further infill drilling activities. In this paper, we present four examples of reservoir surveillance activities in different mature North Sea reservoirs. Each example was selected for illustrating the application of a particular surveillance technology to meet a specific objective. Applying the appropriate measurement tools and techniques is essential to the success of the well intervention. Further, in some cases the results can be surprising and lead to unexpected benefits, as will be described in one of the following examples. Fluid flow regimes in vertical, deviated and horizontal wells In a system with multiphase flow, buoyancy causes the fluids to separate into different phases with a mixing layer in between. Gravity ensures that the lighter phase travels at a faster speed than the heavier phase. The difference in velocity between the phases is referred to as slip velocity. This also causes the downhole holdups to be different from the surface cuts.

The ultimate goal of excellence in brownfield management is to increase the value of a field through maximizing production and ultimate recovery within its remaining economic life. The ability to successfully apply reservoir management techniques is essential in meeting the challenges of optimizing late life production. Further, the standardization of operating procedures yields benefits both in terms of optimizing the use of technical resources and in successfully meeting well intervention objectives. It also facilitates and promotes an active collaboration between the operator and service provider, both during logging operations and later when the log data is evaluated and interpreted.We will demonstrate the benefits that the successful development and implementation of robust Standard Operating Procedures (SOP's) for cased hole reservoir monitoring can have. These will be illustrated with recent examples from the Brent Field in the UK North Sea. Developing these SOP's was not a simple process, and required a detailed understanding of the rock & fluid properties, reservoir production mechanisms and contact movements, topsides constraints, and reservoir behavior coupled with experience in data acquisition & interpretation methods which are tailored to meet the specific challenges of the field.The SOPs have been applied to meet a range of specific challenges such as the identification and perforation of gas zones, differentiating reservoir fluid type (e.g. formation/injection water and oil) to access bypassed oil, contact monitoring, and identifying impairment to increase production rates. Success in the development and application of SOPs requires service company involvement and cooperation in all aspects: program design, data acquisition (including real time support and monitoring to ensure data quality), processing, presentation and interpretation. Examples will be provided of how this involvement has contributed to the successful outcome of interventions in the Brent field.