bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development and Qualification of a New Wireless Controlled Retrofit Safety Valve: An Alternative to Well Workover that Enhances Well Safety and Maximizes Production Uptime
Authors: Champion B. P. , Gandini G. , Gabbiani A. 
Published: July 2010

Abstract
There are many examples of wells around the world today that are shut-in due to failure of the Surface Controlled Sub-surface Safety Valve (SCSSV). Whilst these valves are generally very reliable, the control line that runs to surface in the annulus is susceptible to plugging by contaminants in the hydraulic control fluid and also to corrosion, which causes leaks; both are outcomes that render the valve inoperable. The failure of the control line also means that the contingency solution of installing a Wireline Retrievable Surface Controlled Sub-surface Safety Valve (WR-SCSSV) is not possible.
When a safety valve fails, the most common remedial solution today involves installing a Sub-surface Controlled Safety Valve (SSCSV), such as an ambient valve or storm choke. Whilst this solution is lower cost and more straightforward than performing a full rig-based well work over, it is not as safe. SSCSVs are directly influenced by changing well flow conditions, such as high flow rates, low pressures, or by water slugs, and thus are notoriously unpredictable in operation. Additionally, they are not controllable from surface and not fail-safe, which is undesirable from a well control and safety standpoint.
By transmitting electromagnetic (EM) signals from surface to downhole, it is possible to control downhole hardware. A wireless controlled safety valve has been developed that can be retro-fitted into a well using conventional slickline intervention equipment and procedures. Being controllable from surface and of a fail-safe closed design, this valve offers both functional and safety advantages over existing SSCSV solutions. This new valve also offers a retro-fittable solution for wells having no hydraulic control line installed. In situations where a capillary string may need to be installed for foam or chemical injection purposes, it also provides an opportunity to free up the hydraulic control line.
A prototype valve was subjected to qualification and functionality testing in accordance with a modified ISO 10432 test procedure. This testing was followed by installation in an onshore gas well for a 6 month trial that involved both flowing and injection phases. The valve was cycled and inflow-tested regularly and performed reliably, consistently and fully in accordance with specification throughout the trial period.
This successful trial of a new wireless controlled safety valve marks the introduction of a more controllable and predictable alternative to an ambient valve or storm choke, minimises deferred production and increases the well's safety. Following the successful onshore trial, the valve is now considered ready for wide scale field application onshore and at the time of writing this paper, plans for performing a first trial on an offshore platform are well advanced.
A New Approach to Thin Oil Zone Modeling in High-Dipping Multilayered Reservoirs
Authors: Tolstukhin Evgeny , Olivier Pierre 
Published: July 2010

Abstract
This paper focuses on maximizing oil recovery from thin oil rim in a high-dipping, multilayered reservoir in the North Sea.
Oil output from thin oil zones between a gas cap and an aquifer is limited to uneconomical rates caused by water coning and gas cresting. Horizontal wells are widely used in thin oil rim development due to the limited pressure drawdown applied to the formation. The horizontal wells should be optimally positioned within the oil zone to avoid premature gas and water breakthrough.
Critical issues for thin oil zone reservoir modeling are correct grid representation of internal heterogeneities, fluid saturation distribution, fluid contacts, horizontal well trajectories and flow displacement properties.
In a stratigraphic grid, the lack of resolution affects the fluid contacts movement within the high-dipping reservoir layers. Similarly for a horizontal grid, thin reservoir intervals are truncated due to a ‘stair-casing’ effect, which leads to loss of communication within the layers.
A hybrid grid was constructed to combine the benefits of the horizontal grid in the oil zone together with the stratigraphic grid in the water and gas zones. Such a grid framework provides the best modeling approach for representing the transition zone and fluid contact movements.
In the study, the prediction of oil, gas and water production in the transition zone was difficult because the crude oil altered formation wettability after hydrocarbon migration and reservoir structure tilting. Multiphase flow was modeled by integrating the key dynamic reservoir controls, translated into end-point correlations above the free water level based on multivariate SCAL data analyses.
Comparative analyses of alternative modeling techniques exhibited clear differences in the response for coning development and optimal well placements.
Modeling and Optimization of Asphaltene Deposition in Porous Media Using Genetic Algorithm Technique
Authors: Hematfar V. , Kharrat R. , Ghazanfari M. H. , Bagheri M. B. 
Published: July 2010

Abstract
Different models have been proposed for deposition of asphaltene on reservoir rocks that due to complexity of asphaltene nature, most of them have not been productive. Here, a reliable model is proposed which despite of previous models, considers the change in asphaltene saturation in the core. The obtained experimental data in the laboratory was used for model validation. In this work, a series of core flooding tests was carried out in presence of connate water at different solvent-oil volume ratios. Pressure drop was measured at three different terminals along the core. The obtained experimental data as well as mass balance equations, momentum equation, asphaltene deposition and permeability reduction models were employed in an iterative scheme to simulate the deposition process. Genetic algorithm (GA), which is a powerful tool, was applied for history matching, optimization and determination of the model parameters. Well match observed between the model results and experimental data confirms the accuracy of the proposed mathematical model of asphaltene deposition in porous media. Also, applied improvement on the model resulted in accurate simulation as well as determination of precipitated asphaltene saturation. Optimization shows that all deposition mechanisms, surface deposition, entrainment and pore plugging, are dominant during the permeability evolution process. Results of this work can be helpful for reliable simulation of the dynamic asphaltene deposition process during different production schemes.
Deployment, Monitoring and Optimisation of a Scale Inhibitor and Associated Corrosion Inhibitor within a Deepwater Subsea Facility, Offshore Brazil
Authors: Jordan M. , Linares-Samaniego S. , Santos Afonso M. 
Published: July 2010

Abstract
This paper presents field results and lessons learned from an FPSO, Offshore Brazil where a scale and corrosion inhibitor has been applied subsea to control both the deposition of scale and associated corrosion.
The paper outlines the problems encountered when the initial scale inhibitor formulation was deployed in the field related to materials compatibility with the subsea manifold and the steps taken to develop and monitor an improved formulation. Problems that can affect product application in a subsea environment, including deposition of suspended solids within the chemical, hydrate formation, incompatibility of the chemicals with umbilical material and produced fluid, will all be addressed. The laboratory methods used to select the product along with measurement methods used in the field are also discussed. The validation of the laboratory selection methods in the field required the development of a monitoring program to establish base line control and to assess the degree of protection from scale deposition and corrosion across the process.
The use of novel real time scale monitoring, as well as water chemistry tracking proved vital to the understanding of the efficiency of flow assurance within the processes and how treatment rates of the scale inhibitor and corrosion inhibitor could be optimised.
This paper will outline in detail the particular issues associated with chemical injection to a subsea facility, many of which are currently being developed in the Gulf of Mexico, offshore West Africa and Brazil. This case study is a good example of lessons learned and sharing of best practice from another oil basin.
FAST Optimization of Line-drive Water Injection
Authors: Lafond Kim Bousquet , Pedersen Lars M. , Christiansen Lars Bo 
Published: July 2010

Abstract
The Halfdan Field has been developed with long parallel horizontal wells using alternating producer/injector pairs (Figure 1). Using the Fracture Aligned Sweep Technology (FAST) the injectors were hydraulically fractured along the wellbore to increase injectivity and enhance the sweep geometry. The anticipated FAST fracture orientation has been verified by 4D seismic interpretation and confirms the geomechanical concept of FAST.
As reservoir pressure increases the fractures tend to close. This provides an opportunity to further increase injection pressure. However, the risk of extending the fracture into the Halfdan spine wells makes it necessary to increase injection pressures in a controlled manner.
This paper provides a method to operate water injection at the field's performance limit. The following tools have been applied, further developed and confirmed by field data.
Fall off testing to Estimate Current Fracture Heights: Analysis of more than 200 falloff tests to estimate fracture height and to identify opportunities for increased injection rates. Step Rate Tests to Increase Injection at Unchanged Fracture Height: Execution and analysis of more than 60 Step Rate Tests to increase injection rates at constant fracture height. Controlled Fracture Criterion to Control Fracture Propagation: Development of correlations for fracture height vs. injection pressure and fracture opening pressure vs. voidage to identify performance limits and improve the control of the fracture propagation.
An average pressure gain of 80 psi per injector corresponding to a total of 8,000 bbl/d of injected water has been achieved for the 26 Halfdan water injectors. The incremental oil gain from this is estimated at 3,500 bbl/d. Better fracture height control and propagation, securing reserves by lowering the risks of producer-injector short circuits, has been achieved through an improved understanding of fracture behavior from fall off tests and correlation between pressure, rates and voidage. This method has successfully been applied at field scale with proven results and is refined with the acquisition of new field data.
Development of a Data Partition Technique for Gradient-Based Optimization Methods in History Matching
Authors: Ding D. Y. 
Published: July 2010

Abstract
Assisted history matching is now widely used to constrain reservoir models. However, history matching is a complex inverse problem, and it is always a big challenge to history match large fields with a large number of parameters.
In this paper, we present a new technique for the gradient-based optimization methods to improve history matching for large fields. This new technique is based on data partition for the gradient calculations. The objective function is first split into local components, and the dependence of each local component on principal parameters is then analyzed to minimize the number of influential parameters. The interaction between parameters and local components is allowed in the splitting. Based on this study, we can propose a perturbation design, which allows us to calculate all derivatives of the objective function with only a few perturbations. This method is particularly interesting for regional and well level history matching, and it is also suitable to match geostatistical models by introducing numerous local parameters. This new technique makes history matching with a large number of parameters (large field) tractable.
Effect of Shaped Charge Case Materials on Perforating Guns
Authors: Han C. , Du Michael H. , Ference Bob 
Published: July 2010

Abstract
Detonation of shaped charges carried by a perforating gun creates a complex physical and chemical process that occurs within a very short time. During the process the shaped charge case usually disintegrates and is partially oxidized. The oxidization emits heat in addition to that of the explosive detonation and hence could eventually affect the post-detonation condition of the perforating gun.
Zinc and steel are common materials used in the manufacture of shaped charge cases, but their physical and chemical properties result in quite different impacts on the performance of the perforating gun and on its survivability. About 1,000 ms after detonation, a charge with a zinc case generates a pressure approximately 50% higher than one with a steel case. The zinc case creates an impulse about 30% higher and a temperature about 220°F higher. It results in more than 45% oxidation; for the steel case oxidation is less than 5%. Conversely, the zinc and steel case contributions to the detonation process are quantifiable in terms of energy. Such a quantified study is first reported in respect to perforating. Details can be incorporated into a recently developed gun survivability model for risk management in both new perforating product development and job execution. In field operations it can be used in post-perforating evaluation of formation damage.
Numerical Modelling of a Well Test Affected by Condensate Banking and Comparison with Analytical Interpretation
Authors: Botteon A. , Monico C. 
Published: July 2010

Abstract
Condensate banking consists of a liquid accumulation in the formation around a gas well when pressure drops below dew point. This can strongly compromise well deliverability. A numerical simulation study was carried out to reproduce data measured during a DST test in an exploration gas well where condensate banking had been assumed based on analytical interpretation.
A compositional radial model was built to study the evolution of fluids in the formation around the well. Numerical simulation captured the generation of condensate banking at the producing conditions of the DST. An analysis of simulated build-up pressures showed qualitative agreement with actual data in the double stabilization of the derivatives. Sensitivities were performed on the critical oil saturation above which condensate is mobile and on the permeability anisotropy ratio.
The effects of velocity dependent relative permeability and non Darcy flow were also investigated.
A match was obtained between the numerical simulation output and the analytical interpretation results in terms of radial extension of condensate banking and pressure build-up derivative.
Numerical simulation validated the classic analytical interpretation of well test and also provided a more accurate comprehension of condensate distribution in the vicinity of the well. This demonstrated the capability of a simulation model to reproduce the condensate banking process and the effects on build-up pressure. Moreover, the sensitivity results limited the uncertainty on investigated parameters.
Well test modeling provides a powerful method to confirm the possible formation of condensate banking based on analytical interpretation results.
Applying Multi-Node Intelligent Well Technology for "Active" Control of Inflow Profile in Horizontal/Inclined Wells
Authors: Sun Kai , Guo Boyun , Saputelli Luigi 
Published: July 2010

Abstract
Non-equalized production influx along the horizontal or inclined wellbore is believed to be responsible for early water/gas breakthrough in oil production wells. Non-equalized water injection distribution has been recognized to cause poor sweep efficiency in waterflooding. The non-equalized fluid flow is attributed to reservoir heterogeneity and frictional pressure drop along the wellbore. A practical means of minimizing the problem is to use inflow control devices (ICD) between isolation packers to adjust the production influx or injection distribution within the isolated compartments. However, the ICDs are passive devices, i.e., once they are set in place in a completion string they cannot be adjusted to ensure equalized flow when reservoir conditions change during oil production or water injection. This paper introduces a new technology called Multi-Node Intelligent Well System (MNIWS) that is under development and will be soon available to the industry.
Starting with analyzing the data from an existing horizontal well with an ICD installation, we derived a new completion design for oil production wells using the MNIWS. Computer modeling of well performance shows that the MNIWS technology suite can equalize production influx and delay water breakthrough into the horizontal wellbore more effectively than conventional ICDs; in particular when inflow conditions change during the well's life.
Inhibition of Sodium Soap Emulsions, West Seno, Indonesia Field
Authors: Gallup Darrell L. , Denny Vitus , Khandekar C. Y. 
Published: July 2010

Abstract
In the Kutei, Indonesia oil and gas producing basin, a serious flow assurance problem has occurred in the form of an oil-water emulsion. This emulsion, formed via the reaction of carboxylic acids in oil with sodium-chloride-bicarbonate-acetate produced water, is difficult to break. At the West Seno deepwater field, the floating production unit (FPU), utilizes heat and an acidic demulsifier to break the emulsion into salable oil and water suitable for overboard discharge. Over the past couple of years, a few wells have begun to produce an emulsion that is not easily broken by the FPU heat/acid demulsifier process. Characterization studies of the new emulsion show that it is very different chemically from the common sodium soap emulsions produced at West Seno field since production inception in 2003. The former contains primarily sodium alkyl benzoates, while the latter consists primarily of sodium n-alkanoates ranging from C10 – C36. Oil produced from the wells that produce the new "difficult" emulsion is waxier than normal. The combination of waxes and the alkyl benzoic acids is apparently responsible for the formation of the "difficult-to-treat" emulsion.
Laboratory screening tests of new sodium soap emulsion inhibitors have shown that heat and several non-acid inhibitors break the emulsions more efficiently than the incumbent acid demulsifier. One new inhibitor was especially efficient and more cost effective than all other inhibitors included in the study. Not only is this new inhibitor more effective at a lower dosage, but its bulk price is also less. This inhibitor was injected into two West Seno wells that produce the "difficult" emulsion in a short field trial. Coupled with reservoir heat, the inhibitor successfully broke the emulsion at a reasonable dosage. The chemical appears to inhibit sodium alkyl benzoates and sodium n-alkanoates via a complexation mechanism. We are now preparing for commercial deployment of the new inhibitor in West Seno wells. We believe that the new inhibitor will eliminate or reduce the need to treat fluids on the FPU with the incumbent acidic demulsifier, which should reduce corrosion and by-product scaling caused by the incumbent.
Selection of Filler Materials to Minimize Preferential Weld Corrosion in Pipeline Steels
Authors: Mahajanam Sudhakar P. , Joosten Mike W. 
Published: July 2010

Abstract
Preferential weld corrosion (PWC) has long been a problem in the oil and gas industry for pipelines used in process facilities, seawater injection, produced water service, offshore platforms, and downhole production systems. This paper reviews recent PWC field failures in light of mitigation guidelines from existing literature. Environmental effects take precedence over chemical composition and microstructure in determining PWC susceptibility. Therefore, the primary approach to minimize PWC is continuous corrosion inhibition. The ideal PWC prevention method would be the use of autogenous welds or welds made with matching consumables. However, this is not a practical option in the field where most pipelines are typically made from carbon-manganese steels with broad chemical compositions, thereby making them susceptible to PWC. The feasible alternative is to use filler materials with strict compositional control vis-à-vis the following elements: nickel, silicon and chromium. In addition, increased preheat and high heat input welding processes should be employed to minimize PWC susceptibility.
Development of Downhole Explosion Monitoring System for Gas Drilling
Authors: Kai Lan , Shugang Hou , Jiaqi Gong , Youming Xiong , Chengkai Li 
Published: July 2010

Abstract
Continental strata in Northeast Sichuan presents poor drillability due to high formation pressure, which leads to low ROP, wellbore inclination and lost-circulation with mud drilling technique. Gas drilling not only dramatically improves ROP and well quality, but also decreases construction cycle. However, this method was apt to trigger downhole explosion through payzones drilling, which would result in downhole tool broken, drilling failure and even well abandonment. During the exploitation of gas reservoirs in Northeast Sichuan, downhole explosion has happened in P104-1, P303-1, Y2 and Y3 wells, and these severe accidents provide an important incentive for developing a downhole explosion monitoring system for gas drilling to decrease downhole explosion risk. This paper will focus on the development of this system based on MIC-2718-a high-gain, high-performance multifunction DAS card-and other high-precision chemical sensors, which can monitor the concentration changes of CO2, CO, O2, H2S and CH4 in real-time. Visual C++ was employed to develop the real-time data acquisition and display interface, which are useful to display and save or playback curves of real-time data, what's more, intelligent alarm function is also available. This system features simple installation, convenient wire routing and great system stability. Furthermore, the usage of new developed downhole explosion monitoring system provides a safe downhole environment for gas drilling.
Bringing Wireline and Coiled Tubing to New Frontiers on a Light Well Intervention Unit
Authors: Drange C. 
Published: July 2010

Abstract
The paper will discuss the introduction of a new method of completing wells whilst reducing the amount of time spent by rigs on each well drilled.
The information presented in the paper will enable operating companies to rethink their way in which they use their drilling rigs, and allow for more of the completion phase to be performed by lighter services such as coiled tubing and wireline.
Based on this new method of completions, up to 9 days per well can be saved on rigs per well. By utilizing this new method of completing wells, allows coiled tubing and wireline to move into a more dynamic market from a light well intervention vessel with a stiff riser solution.
This paper will explain how the use of coiled tubing and wireline in a much more effective way on subsea wells will increased the income of the operating companies, increase the use of known technology on wells where this has not been available before and explain how this set-up will allow for operations in harsh conditions from light well intervention units.