Multiwell injectivity for storage of CO2 in aquifers

AbstractGeological storage of CO2 in deep saline aquifers has been suggested as a potential methodology for reducing CO2 e missions over short to medium terms. A number of projects are in operation and a larger number are being designed. However, not all aquifers are equally suitable for CO2 storage. Virtually all publications that present the criteria for selection of suitable sites for geological storage of CO2 in aquifers, consider injectivity to be among the top three criteria, with capacity and containment being the other two. Among parameters that affect injectivity, permeability can vary by the largest degree. Unfortunately, selection of storage sites with sufficient permeability that would enable injection of the desired volumes, using only one injection well–such as that achieved in Sleipner–is not always possible. When this is not possible, injectivity needs to be improved for example by increasing the contact area with the formation (e.g. through application of hydraulic fracturing or horizontal wells) and/or employing more than one injector. Recent studies indicate that multiwell injectivity does not increase linearly with the number of injectors. Instead, progressively more number of wells is required to achieve an equal increment in injection rate.It is well known, that because of the small compressibility of the water, it takes a short time for the pressure pulse from the different injectors to cause significant interference. We use this observation and suggest a well pattern that would minimize such interference effects in an open and homogeneous aquifer. Next, we develop an analytical solution, for the injectivity of multiwell systems as a function of (i) number of wells, (ii) distance between wells, and (iii) injectivity of one wel.. The analytical solution obtained for single-phase flow is applied to cases of CO2 injection in aquifers. Numerical experimentation over a wide range of parameters demonstrates the applicability of the analytical solution for two-phase flow problems.This relation is developed for homogeneous aquifers; suggesting that such a relationship may be used for scoping and screening studies early on when data us scarce, and the effect of the number of wells and/or their distance on overall injectivity is being studied. Furthermore, such a relationship allows examining the economic balance between increasing the number of wells or the distance among wells

Partnering with Practice: How Partnerships can be Developed, Shared and Managed

Partnerships between business schools and practice are an area of underused potential. In their recent report, the AACSB (2012) recognizes the need for a stronger connection between education and practice and stresses that schools need to articulate the impacts of their investments in scholarship on students’ educational experiences and on the broader communities they serve. In this paper, we discuss our partnering experience that we undertook to integrate an enterprise resource planning (ERP) system into our curriculum. ERP systems pose a significant technical challenge due to their complexity. We discuss the importance of developing a partnership with practice and how such a partnership offers a solution to our problem of working with a complex system in our courses. We detail a partnership with a consulting company with significant experience with ERP systems and a commitment to education. We outline how a practice partner can collaborate with faculty to enhance students’ educational experience. Developing good working partnerships between practice and academe, if done effectively, can provide an opportunity to bring educational value to a new height

Performance Analysis of RIP, EIGRP, and OSPF Using OPNET

Routing protocols are key elements of modern communication networks. Currently deployed dynamic routing protocols that are used to propagate network topology information to the neighboring routers are Routing Information Protocol (RIP), Enhanced Interior Gateway Routing Protocol (EIGRP), and the Open Shortest Path First (OSPF) protocol. The choice of the right routing protocol depends on a number of parameters. In this paper, we use OPNET Modeler to analyze the performance of RIP, EIGRP, and the OSPF protocols, which are commonly deployed in Internet Protocol (IP) networks. We designed various simulation scenarios to compare their performance. 1

Exploring the Performance Benefits of End-to-End Path Switching

This paper explores the feasibility of improving the performance of end-to-end data transfers between different sites through path switching. Our study is focused on both the logic that controls path switching decisions and the configurations required to achieve sufficient path diversity. Specifically, we investigate two common approaches offering path diversity – multi-homing and overlay networks – and investigate their characteristics in the context of a representative wide-area testbed. We explore the end-to-end delay and loss characteristics of different paths and find that substantial improvements can potentially be achived by path switching, especially in lowering end-to-end losses. Based on this assessment, we develop a simple path-switching mechanism capable of realizing those performance improvements. Our experimental study demonstrates that substantial performance improvements are indeed achievable using this approach