Successful Hydraulic Isolation Assessment Saves Rig Utilization Time and Unnecessary Cement Remedial Squeeze Operation - Case Study, Kuwait

While drilling an 8 1/2-incli section of a north Kuwait producer well, severe mud losses were encountered. Hence, it was decided to design a light weight cement for the 7-inch liner section to avoid further losses while pumping the slurry. The main objective was to achieve a hydraulic isolation to avoid any heavy remedial intervention and potential dump flood behind the liner from the high-pressure Lower Burgan (LB) to Shuaiba. Full suite of well integrity logs were ran to properly assess whether enough hydraulic isolation was in place. To evaluate the bonding quality of the cement, two independent measurements were carried out across the 7-inch liner with the ultrasonic and sonic bond logs. A subsequent temperature survey was recorded to determine any geothermal anomaly, which could be indicative of fluid movement behind the casing. Finally, oxygen activation stations were conducted based on the cement log and temperature surveys to assure no water movement behind the casing. The ultrasonic and sonic bond log measurements showed an acceptable bond quality generally. However, the top part of Shuaiba formation up to LB exhibited relatively lower bond quality. The subsequent temperature and oxygen activation logs indicated that the zonal hydraulic isolation was achieved by showing no water movement behind the 7-inch liner. The two complementary surveys helped to take the proper forward decision for this well to go ahead with the planned perforation without cement remedial squeeze, since enough hydraulic isolation was proved to be in place behind the 7-inch liner. Additionally, this saved the rig utilization time and cost by avoiding unnecessary remedial operation. This is usually a heavy-duty operation, which takes time and induces holes in the casing that should be avoided, knowing this type of operation only provides a very marginal gain in terms of isolation. Furthermore, the well is currently producing at 0% water cut after completion. The proper cement design using light weight cement and optimized casing-landing plan were crucial to achieve good cement placement against formation. The use of the right well integrity approach helped to confirm that effective hydraulic isolation was achieved. Hence all these efforts resulted in the saved rig utilization time and cost by avoiding unnecessary squeeze intervention.

An Approach to Fine Tuning Database Performance in Application Software

Database tuning is crucial step to enhance the performance of the application software. There are many tools available in Microsoft to evaluate the performance of the stored procedures and identify them. This paper presents a comparative performance of actual and tuned sample stored procedures in SQL Server 2008 R2 of Application software (Microsoft). The results showed there is a marginal gain in the efficiency after the database tuning.

Towards an efficient weighted random walk domination

In this paper, we propose and study a new problem called the weighted random walk domination. Given a weighted graph G ( V, E ) and a budget B of the weighted random walk, it aims to find a k -size set S , which can minimize the total costs of the remaining nodes to access S through the weighted random walk, which is bounded by B. This problem is critical to a range of real-world applications, such as advertising in social networks and telecommunication base station selection in wireless sensor networks. We first present a dynamic programming based greedy method (DpSel) as a baseline. DpSel is time-consuming when | V | is huge. Thus, to overcome this drawback, we propose a matrix-based greedy method (MatrixSel), which can reduce the computation cost greatly. To further accelerate MatrixSel, we propose a BoundSel approach to reduce the number of the gain computations in each candidate selection by proactively estimating the upper bound of the marginal gain of the candidate node. Notably, all methods can achieve an approximation ratio of (1 - 1/ e ). Experiments on real datasets have been conducted to verify the efficiency, effectiveness, memory consumption and scalability of our methods.

Reform of VAT and special tax regimes: The tax system harmonization

Subject. This article considers the issues of harmonization of tax regimes and reform of special tax ones. Objectives. The article aims to determine areas to improve the tax system, harmonize the General Tax System and special tax regimes, and involve business entities applying special tax regimes in the VAT movement. Methods. For the study, I used the methods of logical analysis and synthesis, induction and deduction. Results. The article offers a concept of harmonization of the General and Simplified Tax Systems, and the Unified Agricultural Tax. As well, the article substantiates the need to combine the Simplified Tax System and Unified Agricultural Tax, and limit the marginal gain for the application of special tax treatments. Conclusions and Relevance. The preconditions that led to the introduction of the Simplified Taxation, Unified Agricultural Tax and Unified Tax on Imputed Income special tax treatments are not relevant today. A fresh approach to special tax regimes is needed in the context of the digitalization of the tax system. The results obtained can be used in legislative activities to reform the tax system.

An advertisement dissemination strategy with maximal influence for Internet-of-Vehicles

The recent advances in computation and communication technologies have led to the emergence of Internet-of-Vehicles where vehicles are connected to each other through sensors so that they can exchange information to improve driving safety, efficiency, and comfort. Internet-of-Vehicle has attracted attention from both academia and industry, as it promises huge commercial and research value. This article studies an advertisement dissemination problem in Internet-of-Vehicle with an aim to maximize the profit (number of vehicles to receive advertisements) given a limited budget. In this problem, advertisements will be first sent to a selected set of seed vehicles, then forwarded to neighboring vehicles. To find the influential set of vehicles, we examine the probability of interaction between vehicles by exploiting their mobility. In particular, we present the computation of node marginal gain in four cases by examining vehicle connectivity and topology. Simulation results demonstrate that the proposed algorithm outperforms existing methods for influence maximization by running time and deliver ratio under different traffic scenarios.

Using Greedy Random Adaptive Procedure to Solve the User Selection Problem in Mobile Crowdsourcing

With the rapid development of mobile networks and smart terminals, mobile crowdsourcing has aroused the interest of relevant scholars and industries. In this paper, we propose a new solution to the problem of user selection in mobile crowdsourcing system. The existing user selection schemes mainly include: (1) find a subset of users to maximize crowdsourcing quality under a given budget constraint; (2) find a subset of users to minimize cost while meeting minimum crowdsourcing quality requirement. However, these solutions have deficiencies in selecting users to maximize the quality of service of the task and minimize costs. Inspired by the marginalism principle in economics, we wish to select a new user only when the marginal gain of the newly joined user is higher than the cost of payment and the marginal cost associated with integration. We modeled the scheme as a marginalism problem of mobile crowdsourcing user selection (MCUS-marginalism). We rigorously prove the MCUS-marginalism problem to be NP-hard, and propose a greedy random adaptive procedure with annealing randomness (GRASP-AR) to achieve maximize the gain and minimize the cost of the task. The effectiveness and efficiency of our proposed approaches are clearly verified by a large scale of experimental evaluations on both real-world and synthetic data sets.

Assessing risk of prosthetic joint infection

This chapter discusses assessing the risk of prosthetic joint infection (PJI) and includes discussion on high-risk patients (classified by age, skin colour, extracellular matrix, cellular turnover, diabetes, obesity, rheumatoid arthritis, previous periarticular fractures and skin disorders). The aim is to allow the practitioner to identify high-risk patient attributes that can be positively influenced such that the risk of PJI is reduced. There are some patients with more than one risk factor and, as such, every effort must be made to reduce each even if there is a marginal gain in each. Delaying elective surgery until the risks of PJI are reduced must be encouraged but must be balanced with alleviating patient symptoms.