bluuebunny/crossref_metadata_2025_split huggingface dataset:
Integrating Pressure Transient Analysis and Production Analysis for Dynamic Reserve Evaluation in Tazhong 1 Ordovician Carbonate Gas Field, Tarim Basin
Authors: Hedong Sun , Ying Shi , Shiyin Li , Bo Kang , Linlin Lu , Zhicheng She , Yanchun Li 
Published: May 2016

Abstract
Tazhong ?gas field is a typical vug-fractured marine carbonate gas condensate reservoir with characteristics of high heterogeneity and complex geological& dynamics, of which grand challenges face the development by using the classic evaluation method of dynamic reserves. On the basis of literature research, a formal definition about dynamic reserves is given. Besides, a workflow of dynamic reserve for carbonate gas condensate reservoirs is built relying on the long-term low accuracy data of daily production and short-term high-accuracy data of pressure build-up testing, which integrates full lifecycle short-term pressure transient analysis and long-term production analysis combined with the geological understanding. The factors affecting reserve estimate are analyzed based on a field application on Tazhong ?gas field, including initial formation pressure, PVT, the error of pt~pwf conversion, production time, producing water and routine of work. The simulation results show that the gas-liquid two-phase pseudo-pressure method is more appropriate than the pseudo-single phase method for calculating dynamic reserves for low gas-oil ratio gas condensate wells. The workflow can improve data utilization ratio, reduce the uncertainty of reserve estimation, avoid the development risk, optimize the development plan, and contribute the enhanced oil recovery in the late stage. It can be also used in other marine carbonate reservoirs. Recently, three thousand large-scale condensate gas fields have been discovered in the Ordovician carbonate reservoir of the Tazhong area, which is located in the middle part of the central uplift belt in the Tarim Basin?1-2?. However, the traditional material balance method for doing what is not applicable in this area due to many factors. First, the type of reservoirs is various, including cavity, fracture-vug, cleavage and matrix pore (dominant). Second, the flow mechanism is complicated, including seepage and conduit flow. Besides, fluid property is complex in nature, leading to low-, middle-, high condensate and volatile gas reservoirs. Third, controllability is low during the development, the production model involves non-constant pressure and non-constant rate. Fourth, it is difficult to calculate the bottom hole flowing pressure due to the small difference between the formation pressure and the dew point pressure, there is the retrograde condensation phenomenon in formations, and multi-phase flows happen in the wellbore. Fifth, there are few hydrostatic gradient data, and they do not decrease monotonically. Therefore, a great challenge facing developers is how to evaluate the dynamic production of complex carbonate gas condensate wells under the complex production status.
Productivity Improvement Using Combination of Static and Dynamic Underbalanced Perforation in Tahe Oilfield, Tarim Basin, West China
Authors: Fuqiang Lei , Lian Liu , Li Liu , Yong Hu , Gang Zhao 
Published: May 2016

Abstract
In concern with the skin factor value, the key significant components which do not directly depend on the nature of the reservoir properties are drilling/completion fluid invasion damage and perforating induced damage. The oil &gas industry has been tried to eliminate the fluid invasion issue by applied deep penetration perforating to bypass the invasion zone and reach un-invaded reservoir. Lots of experiences and lab analysis shows that perforation performance is not meet the expectation of the productivity because of the perforation induced damage. As for now, static underbalanced perforation has been recognized by industry as one of the method to obtain clean perforation tunnel. However, static underbalanced perforation method is not always giving the expected productivity result.
Experiments showed that the cleanup of the perforation tunnel was not totally dominated by the static under-balance pressure but also the transient pressure during the first 100 milliseconds of perforation or dynamic under-balance. The dynamic under-balance can be obtained by creating an instantaneous drop in pressure around the guns during perforating. The combination of static and dynamic underbalanced perforation with deep penetration charges which be able to bypass an invasion zone, can create a clean tunnel, and significantly reduce the post-perforating damage by killing fluid, and finally maximized the productivity.
This combination of the static and dynamic under balance method has been applied in Tahe Oilfield. Tahe oilfield is located in Tarim basin with reservoir horizon depth of 4100m-4600m, temperature of 94–103, and pressure gradient is about 1.1MPa/100m. The payzone is Triassic clastic reservoir with middle porosity and permeability quality. The static underbalanced with different deep penetration charges of perforating system has been applied in Tahe oilfield to improve the productivity. However, the statistic showed that productivity is not reaching the expectation range by static underbalanced perforating. The combination method of static and dynamic under-balance perforation along with deep penetration charges was applied in 2011 to WELL-1. The well productivity was exceeded the expectation and the PI value is almost 2.5 times compare to offset wells which only using static under-balance perforation method. The pressure transient analysis result proved the improvement by showing negative skin value.
This paper will describe the application of this technique in Tahe oil field including: suitable job design, execution of the job and provide the results summary of this successful application. The evaluations of the method are based on productivity improvement and skin value from pressure transient analysis.
Real World Solutions Effective Fracture Treatment Design in Horizontal Wells
Authors: Sturms Jason M. , Smith Charles H. , Ziane Lynda 
Published: May 2016

Abstract
Horizontal wells have altered the ability to deliver production from marginal reservoirs. Although reservoirs with permeability values in the 0.1 to0.01 millidarcy range had been identified in many producing basins, these reservoirs could not be exploited until horizontal drilling became a commercial reality. Drilling these reservoirs became an engineering process that could be applied with great success in many different basins and rock types.
The completion of these resources proved to be a different matter, however. Wells that were drilled with excellent vertical control within the reservoir did not exhibit a consistent response to treatment stimulation along the entire traverse of the horizontal sections. However, reservoirs that were considerably different lithologically were always expected to provide a diversity of completion challenges. Pump-in tests were used in many cases in an attempt to under stand this lack of consistency.
More troubling are the reservoirs that appear to be homogeneous that do not respond well to similar treatment designs along the length of the horizontal section. In some cases, pump-in tests followed by treatment designed from that data failed to yield the expected production results. Sometimes, breakdown could not be achieved in the reservoir.
This paper describes how to apply data derived from dipole sonic logs in horizontal sections of a well to establish the anisotropy along the length of the horizontal section. This information is then used to define the brittleness properties of each section of the wellbore. Perforations are selected to take advantage of this brittleness, and effective fracture treatments are designed and pumped.
Two reservoirs are examined where this application is used. These case studies occurred in different basins, but both were difficult and troubling reservoirs. The fracture treatment success increased from 50 to 60% to 100%,with reduced breakdown pressures.
An Integrated Approach of Fractured Reservoir Modelling Based on Seismic Interpretations and Discrete Fracture Characterisation
Authors: Gong Bin , Li Junchao , Shan Ying 
Published: May 2016

Abstract
An integrated approach of fractured reservoir modeling is presented. First, the fracture density and azimuth distribution of the entire reservoir is mapped from seismic anisotropy analysis and image log calibrations. Then we apply a dynamic workflow to construct the discrete fracture model by connecting fracture elements laterally and vertically. A tetrahedral grid is then generated for detailed reservoir simulation that fully resolves the discrete fracture characterization. Finally the flow simulation is performed on an actual carbonate reservoir block in the Mideast. This study presents a systematic way of modeling and simulating fractured reservoirs.

Introduction
Fractured reservoir modeling remains a challenge given that realistic fracture characterization is difficult due to no highly-recognized algorithms to derive field-scale fracture properties from seismic processing results. Recent advances in seismic and image log interpretations enable realistic modeling of naturally fractured systems, though with significant uncertainty. Consequently, it is possible, to certain extent, to represent actual fracture distribution in reservoir modeling and run detailed simulation via a discrete modeling approach (Gong, 2006 and 2008).
Knowledge Management in Engineering Activities of an Operating Company
Authors: DiLiddo G. , Gabetta G. , Ponti F. , Cavassi P. , Fassina P. 
Published: May 2016

Abstract
A better Management of Knowledge is an actual need in the Oil&Gasindustry. In the past years, as a matter of fact, the amount of information available to engineers and scientists increased exponentially thanks to developments of the ICT tools making therefore harder to handle it. On the other hand, industry practice is to keep the plant running, implying that decisions have to be made quickly and time is short to collect and examine all the possible information.
A solution to these challenges is Knowledge Management, which is defined as the ensemble of processes that allow to capture, validate, consolidate, archive, re-use and diffuse knowledge in order to improve both business processes and innovation processes. To make it happen, new ICT tools and mindsets need to be developed and exploited.
In Eni E&P Division, a Knowledge Management System (KMS) is operating since 2004 with the aim at facilitating and speeding-up the sharing of best practices, lessons learned and other Know How across the organisation; several ICT tools are employed, such as forums, mailing lists, SharePoint websites, webinars etc. The KMS is based on several Communities of Practice, which have the aim of conveying technical debate transversally to different disciplines and to the entire eni group, which is heterogeneous due to geographical location, culture, industrial sectors and discipline involved. The resulting interactions, moreover, bring the advantage of making explicit (and durable) all the personal knowledge of the members that would otherwise got lost due to turnover and distance among the employees.
Taking into account the results of the first few years of implementation of the KM system in the engineering area, this paper will summarize the successes and lessons learned during the operating life of the Communities, to trace a road map for the future work.
Mitigation of Deepwater Shallow Hazards with Simplified Cement System: South China Sea Case Study
Authors: Ellis Todd B. , Acorda Edgar Paul R. 
Published: May 2016

Abstract
Cementing is one of the most critical steps in the well construction phase. Qualified cement integrity is considered a barrier to inhibit fluid migration to surface. For conventional wells, cement in addition to barriers such as BOPs (Blow Out Preventers), fluid hydrostatic pressure, and mechanical methods are used to ensure fluid migration is inhibited. For top-hole sections of deepwater exploration wells however, cementing is your only barrier to mitigate uncontrolled fluid flow to the seabed. During the top-hole operations (typically 36-in. and 26-in. hole sections), the bore hole is drilled without a riser and returns are taken to seabed. This creates difficultly in controlling shallow hazards such as gas hydrates and shallow water flow because the well cannot be killed using conventional methods. To assure mitigation of shallow hazards, an emphasis is made on achieving short transition times for cement designs.
For South China Sea operations, it is common practice to incorporate cenospheres (dry blended lightweight additive) into the cement design to ensure suitable properties are achieved. However, the use of cenospheres requires blending onshore and excess blends to be shipped offshore for contingency purposes. Although required slurry properties can be achieved with cenospheres; logistical issues, left over disposal concerns, costs, and low cenosphere pressure ratings create a complex operation. In addition, cement systems should be designed to incorporate loss of lightweight material during transfer offshore, and must account for higher down-hole densities due to crushing of lightweight cenospheres. All of these processes require great emphasis on Quality Assurance / Quality Control (QA/QC) and economic concessions.
Other unique challenges that must be accounted for are low temperatures, commonly around 4°C (50° F) at seabed, low fracture gradients, enlarged hole sizes due to high rate of penetration (ROP) drilling, and environmental regulations due to returns at seabed. The cement system must be designed for all the above aspects, and still maintain excellent integrity to enable the BOP stack to be installed upon a firm foundation.
This study will describe a new simplified cement system which exhibits excellent slurry properties necessary for a deepwater environment. Laboratory results and engineering procedures will be reviewed to demonstrate that all necessary qualities for mitigation of shallow hazards are met. Furthermore, logistical and HSE advantages will be highlighted, and two case histories will be discussed.
Harnessing Intelligent Field Capabilities for Early Understanding of Reservoir Behavior and Proactive Decision
Authors: Abu-Hassoun Amer H. , Shamrani Sultan S. 
Published: May 2016

Abstract
With recent advancements in field instrumentation technologies and the expansion of Saudi Aramco's state-of-the-art intelligent field infrastructure, a wealth of valuable knowledge is being derived from integrating intelligent field capabilities with best-in-class reservoir management practices. Intelligent field applications have already leveraged real-time reservoir surveillance data to enable timely responses and fast interventions for events observed from real-time data. As richer and more granular datasets are collected from the field, deeper insights and understanding of the reservoirs are gained at fractions of the needed time where intelligent field capabilities are not present. The abundance and timely processing of intelligent field data enables more tactical adjustments in reservoir management strategy. This type of real-time reservoir management has already shown great value in reservoir performance optimization.
This paper discusses several cases in which an intelligent field enabled early detection of anomalies and shortened the time-cycle for an analysis, decision and action. The first case discusses the early detection of localized pressure support anomalies due to poor rock quality. This timely detection, facilitated by intelligent field infrastructure, enabled quick decision making and actions to overcome the anomaly. The second case shows how real-time monitoring of reservoir pressure propagation has helped to detect over-injection in two injectors with malfunctioned meters. This has allowed timely action to ensure uniform pressure propagation and repair of faulty equipment. The third case shows that the utilization of real-time data has assisted in detecting a casing leak in a short time, which helped in making a corrective action to restore the well's capacity.
In all three cases, had an intelligent field not been there, the time-cycle from detection to analysis, and to decision and action, would have been substantially longer, resulting in higher operational costs and an impact on reservoir performance.
Influence of Micro-Computed Tomography Image Resolution on Petrophysical Properties
Authors: Alyafei Nayef , Gharbi Oussama , Qaseminejad Raeini Ali , Yang Jianhui , Iglauer Stefan , Blunt Martin J. 
Published: May 2016

Abstract
Micro-CT scanning is a non-destructive technique that can provide three-dimensional images of rock pore space at a resolution of a few microns. However, these grey scale images cannot be directly input into simulators to predict flow properties; they require image processing to segment the solid and void space in the rock. Dynamic and static single phase properties can then be computed using the images directly or on extracted equivalent network models. In this paper, we study the effect of imaging resolution (five different voxel sizes ranging from 6–20 μm) of Clashach and Doddington sandstone on predicted single phase properties (porosity and absolute permeability) and network properties. Experimental data is used to validate the predictions. The results suggest that the computed porosity was largely independent of resolution and in good agreement with the measured value, while image resolutions of a few microns are sufficient to determine the permeability of a high-permeability rock such as Doddington but may not be sufficient for lower permeability samples. The topologically representative networks are sensitive to resolution, adding additional smaller pores and throats as the resolution is increased. This latter reason was confirmed by a network extraction analysis that indicated the average throat radius was 6 µm, similar to the highest resolution used and insufficient to image all important features of the pore space properly.
Calculations of Equivalent Circulating Density in Underbalanced Drilling Operations
Authors: Ettehadi Osgouei Reza , Yoong William Liew Sin , Ozbayoglu Evren M. 
Published: May 2016

Abstract
Underbalanced drilling using gasified fluids is one of the most widely used methods to drill depleted, low pressure and highly fractured formations. For ensuring a safe and successful underbalanced drilling operation, accurate prediction of the equivalent circulating density (ECD) is very important. Nevertheless, estimating ECD of gasified fluids is not easy due to the complexity of the two-phase fluid flow inside the wellbore. In this study, there are two major focuses considered; i) validation of the accuracy of Beggs& Brill (1973) model on the prediction of pressure losses of gasified fluids in under balanced drilling operation, and modification of Beggs &Brill (1973) model for pressure loss estimation inside the wellbore, and ii) to propose an ECD calculation procedure for gasified fluids by using modified Beggs & Brill (1973) model.
To validate the accuracy of Beggs & Brill (1973) model, experiments were carried out using Middle East Technical University (METU) Cuttings Transport Facility to obtain the pressure losses of gasified fluids in an annulus and their corresponding flow patterns. Air-water mixtures were used with various in-situ air and water flow velocities of 0–120 ft/s and 0–10 ft/s, respectively, at wellbore inclinations of 90°, 75°, 60°, 45° and 12.5° without inner pipe rotation. Pressures were recorded at several points along the annular test section, and pressure distribution along the test section was measured. Meanwhile, flow patterns were determined by the help of a high speed digital camera.
Results showed that although Beggs & Brill (1973) model can estimate pressure losses in low gas and liquid flow rates and low slip ratio between two phases for horizontal and near horizontal annular sections with a reasonable accuracy, this model cannot accurately calculate pressure losses at inclined and vertical annular sections. With some modifications, improved Beggs & Brill (1973)model (by applying suggested procedure) can be used to predict ECD and annular pressure losses of gasified fluids inside the annulus accurately. This information can be directly applied for underbalanced drilling operations when gasified fluids are used.
SMS Skyscrapers
Authors: Khan Jamal , Amidenau Gary 
Published: May 2016

Abstract
This paper offers methodology, guidelines and tools to assist Oil/ Gas plants and other industrial facilities to develop organize and improve local safety programs (SMS) that comply with corporate elements of safety management as in the 11 elements of the "Saudi Aramco Safety Management System". The development is done through a consistent method and format for writing the system elements and its processes. For simplicity, the model is represented by a Skyscraper building "SMS Skyscraper". All model processes include definition of crucial characteristics which are: Purpose, Applicability, Description, Flowcharts, Responsibilities, Training, Performance Indicators, Supporting Tools, Documentation and References.
Once the model is used, it helps achieve and sustain quality in defining HSE processes. The quality of processes drive quality in execution of safety activities. This in turn paves the path for proper identification Hazards and evaluation Risk every addition to improving the accountability culture. The overall objective is to help organizations develop customized "Safety Management Systems" that capture the knowledge and "know-how" in addition to providing tools that foster world class execution. In time, and with the right leadership, this will transform organizational and community safety culture and consequently reduce incidents ON and OFF the Job.
The "SMS Skyscraper" model has been used to develop 100 Safety Management Processes for Khursaniyah Gas Plant Safety Management System (KGP SMS) in the period between February 2009 to March 2010 and is now available on Saudi Aramco intranet portal at http://KGP/SMS. The model has helped Khursaniyah Gas Plant achieve level of ownership of our local SMS in addition to placing the department on the leading edge of safety management in Saudi Aramco. It also helped young individuals in the organization substantially grow their knowledge in safety management.
The model has been reviewed and acknowledged by a handful of safety professionals. It has also been recognized by the Upstream business line in Saudi Aramco as the "go-by" model for development of safety processes. Many other departments in Saudi Aramco are now moving towards the Skyscraper model for comprehensive development of local SMS processes.