bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conformance While Fracturing: Technology Used to Reduce Water Production in North Mexico
Authors: Torres A. , Peano J. , Lopez E. , Ramirez R. , Dalrymple D. 
Published: December 2007

Abstract
Often, the main challenge in producing hydrocarbons in north Mexico is the accompanying large associated water production. In the Cuenca de Burgos field in northern Mexico, operators typically encounter water production of over 400 BWPD following fracture-stimulation treatments. This paper discusses how water production in those fields was significantly reduced using a new conformance-while-fracturing (CWF) method that incorporates a chemical relative permeability modifier (RPM) prepad.
The formations were reported to have high watersaturation levels. Fracture-stimulation treatments performed in similar intervals usually (1) intersected a stringer of water within the targeted interval, or (2) extended into the highly saturated areas above and/or below the interval. Water cuts as high as 50 to 60% had made production of such intervals uneconomical.
Data gathered from the first six months of production on more than seven wells in northern Mexico illustrate the economic benefit of the stimulation treatments using the new CWF technique. In many cases, the treatment has limited water production to less than 20%, and some applications have reduced water production to negligible levels. This paper discusses the job design, field application, and results of several CWF treatments performed in this area between 2004 and 2005.
Rigless Tubing Repair Using Permanent and Retrievable Patches at Prudhoe Bay, Alaska
Authors: Julian J. Y. , Cahalane T. W. , Cismoski D. A. , Burton J. , Savage E. L. 
Published: December 2007

Abstract
In Prudhoe Bay, Alaska, non-rig tubing repairs have become a viable alternative to rig workovers (RWO's) to provide an economic remediation for wells with production tubing by "A" annulus communication. Electricline (EL)-set patches can eliminate tubing communication at a significant cost savings and are particularly attractive in areas where RWO cost is significant, such as offshore, remote, or arctic locations. The advantage of tubing patch repair over a conventional RWO is that there is no need to pull tubing, resulting in the well being returned to service faster. Typical patch deployment costs are less than 5% of the costs for tubing replacement with a RWO. To date, 263 permanent and retrievable tubing patches have been set in 181 wells at Prudhoe Bay.
This paper discusses the history of conventional tubing patches at Prudhoe Bay, recommended pre-patch diagnostics, and the use of 3-D advanced caliper viewing software. The paper also provides a systematic approach for the design and deployment of conventional tubing patches.
On a Well-Test Pressure Theory of Analysis for Naturally Fractured Reservoirs, Considering Transient Interporosity Matrix, Microfractures, Vugs, and Fractures Flow
Authors: Pulido H. , Samaniego V. F. , Rivera J. , Díaz F. , Galicia G. 
Published: December 2007

Abstract
Constant flow, rate solutions are presented for a fractured reservoir with transient interporosity flow in a convolution form, considering matrix, microfractures, vugs and fractures flow.
New solutions are presented for two cases, where there is no primary flow through the microfractures and where the compressive and distensive strength process has created an interconnected system of microfractures. In both cases there is an interaction between matrix, microfractures, and fracture systems.
The numerical inversion was carried out with Stehfest's algorithm. In addition, approximate analytical solution for short and long dimensionless time are obtained and compared with the solution calculated by numerical inversion, providing satisfactory results. The values of the numerical inversion were used to generate the results, presented in terms of the dimensionless groups derived from the approximate analytical solution.
A Multifunctional Gel System To Mitigate Deepwater Drilling Challenges
Authors: Amanullah M. , Boyle Richard 
Published: December 2007

Abstract
Deep water drilling generally encounters additional drilling challenges due to the presence of a suite of drilling hazards such as SWF, gas kicks and blowouts, presence of unconsolidated sand formations, shallow gas and gas hydrate problems, lost circulation problems, sea floor washout and erosion, etc. All these drilling hazards cause a significant increase in total drilling cost. Hence, mitigation of the scope of these deep water drilling hazards is very important for safe and economic completion of deep water wells.
The presence of geologically young, mechanically weak and physically loose unconsolidated formations with high pore pressures, porosity and permeability below the ocean bottom is one of the major causes of deep water drilling hazards. Hence, treatment of such formations while drilling or immediately after drilling by incorporating a multifunctional gel, a chemical and/or a polymer either alone or as an integral part of a drilling mud can reduce the deep water drilling hazards significantly. This paper describes a multi-functional and environment friendly gel system to mitigate some of the deep water drilling challenges.
The newly identified multi-functional gel shows excellent compatibility with fresh, sea and salt water. A 16/30 sand pack was used to represent unconsolidated sand formation encountered below the Ocean bed. Experimental results indicate excellent sealing and reasonable strengthening capability of the additive. Permeability measured before and after treatment of the sandpack indicates more than 95% decrease in permeability compared to the original sandpack permeability. The gel also caused more than 50% increase in the penetration resistance of the sand pack i.e. enhanced the strength characteristics of the sandpack.
Use of Surfactants in High-Salinity Atmosphere: A Nonconfigurational Approach
Authors: Siddiqui M. A. , Al-Dossary K. A. , Bataweel M. A. 
Published: December 2007

Abstract
Commonly used surfactants exhibit cloud point or salting out phenomena in a high ionic environment. These phenomena were interpreted in the literature with configurational aspects of surfactant molecules such as functional groups and ionic nature. This paper presents a non-configurational interpretation of this behavior of surfactants and set a parameter for their selection to be used in that environment to avoid treatment failure, previously not reported in the literature.
The power water injectors in carbonate reservoir in field Q were left stable after drilling using a diesel based completion fluid. The flowback of the completion fluid was not allowed due to presence of hydrogen sulfide gas in high concentrations. Formation damage was expected due to injection of the completion fluid into the formation.
These injectors were planned to be treated by using surfactants that are compatible with high salinity formation and injection waters. Thorough lab investigations were conducted on the formation damage induced by the completion fluid by conducting return permeability tests on reservoir cores and compatibility tests. Various treatment fluids containing surfactants and mutual solvents and combinations of these were prepared. Use of surfactants with low electrochemical properties resulted into sudden precipitation of salts. This behavior of surfactants has been discussed in detail in this paper.
Openhole Cleanup of Deep, High-Temperature Horizontal Wells With a Chelant-Based Acid System—Case Histories From Indonesia
Authors: Wibisono Kunto , Burton Robert C. , Hodge Richard M. , Wijaya Rio , Nieuwland Bastiaan , Cassidy Juanita 
Published: December 2007

Abstract
ConocoPhillips Indonesia Inc. Ltd. is producing oil and gas in various locations in Indonesia, both on and offshore. This paper covers work performed in the Belanak field offshore Indonesia. The field is located in Natuna Sea, north of Indonesia, near the border between Indonesia and Malaysia. The gas produced by the Belanak field is transported to Singapore and Malaysia.
Belanak wells which are drilled in the Gabus Massive reservoir have a bottom hole static temperature of 315°F (157°C). The wells are typically long horizontals (2,300–3,400 ft) with openhole completions utilizing stand-alone screens through the producing interval. The reservoir section is drilled with a water-based Drill-in-Fluid (DIF) consisting of polymer and CaCO3 particles and displaced to a solids-free, DIF prior to running the screens.
Typically, acid is used to degrade water-based DIF filtercake and remove CaCO3 contained in the filtercake. The use of a common acid was not an option for this development because of the high reservoir temperature (&gt;300°F). The combination of high reservoir temperature and long shut-in times after acid treatment lead to a high probability of severe corrosion of the sand control screens. In addition to the corrosion concerns with common acids, the rapid removal of the filtercake with acid could create localized, high leak-off of the treating fluid resulting in an uneven distribution of acid across the horizontal open-hole section.
To overcome these problems, a slow reacting alternative chemical solution was required allowing the stimulation fluid to be placed across the entire horizontal open-hole section before the CaCO3 filter cake was dissolved and before major losses started to occur. The solution was found in the application of a Chelant Based Acid System.
This paper details the application of the Chelant Based Acid System as a means to remove CaCO3 filter cakes in 10 Belanak wells, post treatment well performance, best practices, and lessons learned.
Design of Drill-in Fluids by Optimizing Selection of Bridging Particles
Authors: Jienian Yan , Wenqiang Feng 
Published: December 2007

Abstract
To select bridging agents properly is a critical factor in designing the no-damaging or low-damaging drill-in fluids. Historically, the Abrams's rule has been used for this purpose. According to this rule, the median particle size of a bridging agent should be equal to or slightly greater than 1/3 of the mean pore size for a given target formation. However, Abrams' rule only addresses the size of particle required to initiate a bridge. The rule does not give optimum size or address an ideal packing sequence for minimizing fluid invasion and optimizing sealing.
This paper elaborates an ideal packing approach to solve the sealing problem, with the aim being to minimize formation damage by sealing pores with different size, especially those large pores which usually make dominant contribution to permeability and thereby preventing the solids and filtrate of drill-in fluids from invading into formations more effectively, compared with the conventionally used techniques.
A practical software has been developed to optimize the blending proportion of several bridging agents, so as to achieve ideal packing effectiveness. It is very convenient for use in the field only by inputting some data of formation, such as the maximum pore size or permeability.
It has been confirmed from numerous experimental results that the core sample contaminated by the drill-in fluid designed following ideal packing approach can acquire higher return permeabilities, and have a shallower invading depth, a lower breakthrough pressure as well as a lower dynamic filtration rate than cores contaminated by the drill-in fluid designed applying the Abrams's rule.
The method and its use in selecting the best blending proportion of several bridging agents, focusing on an ideal packing sequence for minimizing fluid invasion, are also discussed in this paper. A carefully designed drill-in fluid using the ideal paking technique (named the IPT fluid) for offshore drilling operations at the Weizhou oilfield located in the west of South China Sea is presented. The near 100% return permeabilities from the dynamic damage tests using reservoir cores prove the excellent bridging effect can be provided by this drill-in fluid.
Leak Detection for Gas and Liquid Pipelines by Transient Modeling
Authors: Wang Shouxi , Carroll John J. 
Published: December 2007

Abstract
The leakage of hydrocarbon products from a pipeline represents not only the loss of natural resources, but also is a serious and dangerous environment pollution and potential fire disaster. So quick awareness and accurately location of the leak event are important to cut down the losses and avoid the disasters.
A leak detection method using transient modeling is introduced in this paper. This method is suitable for both gas and liquid pipelines with comprehensive consideration of the transient flow features of compressible flows and stochastic processing and noise filtering of the meter readings. The correlations for diagnosing the leak location and amount are derived based on the online real time observation and the readings of pressure, temperature, and flow rate at both ends of the pipeline. As an online real time system, great efforts have been paid to the stochastic processing and noise filtering of the meter readings and the models to reduce the impact of signal noise. It is essential too for the robust real time pipeline observer to have the self study and adjustment abilities in response to the large varieties of pipeline configuration, pipeline operation conditions, and fluid properties.
Real application cases are presented here to demonstrate this leak detection method. For example, in the leak detection of a crude oil pipeline of 34.5 km and Φ219mm, this method located the leak at 16.6 km from the pipeline upstream end which is only 0.6 km away from the actual leak location.
Advanced Production Monitoring
Authors: Hooimeijer Martijn , Azmi Mohamad 
Published: December 2007

Abstract
An effective and comprehensive integrated production-system monitoring framework plays an important role in the Smart Fields philosophy to turn data into actionable information and therefore value.
This has been demonstrated by implementing some of the principal requirements for such a framework in the application called Data Broker in Shell.
The Data Broker infrastructure has allowed Shell Engineers to perform exception-based surveillance. Used together with other Smart Fields applications such as FieldWare Production Universe, FieldWare Well Test, IPM and Energy Components, automated event recognition and workflows has freed up engineer's time to do more value added work, such as technical analysis and decision-making – time that would otherwise be spent looking for and validating data from many different sources. The system allows for a more efficient handling of data in terms of efficiency, quality and timeliness in reporting to end-users.
The advent of real-time algorithms, monitoring tools, better integration software, event and workflow application tools allows the above infrastructure to be realised.
Application-Appropriate Drilling Technologies Excel in Managed-Cost Mature-Asset Environments
Authors: Corson C. S. , Madarapu R. , Cerkovnik J. , Walters D. , Walton D. 
Published: December 2007

Abstract
Production in most wells follows a predictable pattern dictated by the decline curve. Initially high production is quickly followed by a long, measured decline. This potentially long decline in production, together with an ever-increasing demand for energy, has resulted in many mature, low production fields. To stem the decline in production in these wells and extend the viable economic life of these assets, operators are increasingly turning to advances in technology. Technologies such as improved slimhole re-entry drilling bottomhole assemblies (BHAs), enhanced reservoir navigation systems, and improved conventional drilling techniques are successfully meeting the challenges of developing mature fields in established oil and gas basins around the world. This combination of techniques and technologies is being used in the Williston Basin to increase the recoverable reserves and improve the present economic value of each asset.
Production from the Williston Basin declined from the time of its initial discovery through the early 1990s. The introduction of horizontal re-entry drilling technologies then revitalized this region.
Targeting these thin beds typically requires extending 4½-in laterals from existing or new vertical 7-in. cased wells. In the recent past, re-entry performance was confined by well placement restrictions, water and salt zones, and available drilling technologies. These requirements restricted the wellpath to relatively tight radius build sections. Together with the drilling difficulties associated with slimhole tubulars, these tight builds often resulted in high drag in the hole, limiting the lateral section to 3,000 to 4,000 ft due to weight transfer and drag constraints. However, in recent applications that did not suffer from such restrictions or the consequences of the water/salt formation hole instability issues, larger radius curves could be incorporated into the wellplan. This increased radius reduced drag in the well program, which together with improved motor technologies and experienced wellsite execution, allowed the 4½-in. re-entry section to achieve world record open slimhole multilaterals. The successful completion of such multilateral wells provide for over 10,000 ft of potential reservoir exposure in this thin bed.
Transport of Small Cuttings in Extended Reach Drilling
Authors: Duan Mingqin , Miska Stefan , Yu Mengjiao , Takach Nicholas , Ahmed Ramadan , Zettner Claudia 
Published: December 2007

AbstractField experience has shown that inefficient transport of small cuttings is a main factor for excessive drag and torque during extended reach drilling; however, very little is known about the transport behavior of small cuttings. In this study, extensive experiments with three sizes of cuttings (0.45 mm-3.3 mm) were conducted in a field-scale flow loop (8 in. × 4.5 in., 100-ft long) to identify the main factors affecting small cuttings transport. The effects of cuttings size, drill pipe rotation, fluid rheology, flow rate and hole inclination were investigated.The results show significant differences in cuttings transport based on cuttings size. Smaller cuttings result in a higher cuttings concentration than larger cuttings in a horizontal annulus when tested with water. However, a lower concentration was achieved for smaller cuttings when 0.25 ppb Polyanionic Cellulose (PAC) solutions were used. Unlike the transport of large cuttings, which is mainly dominated by fluid flow rate, the key factors controlling small cuttings transport were found to be pipe rotation and fluid rheology. Improvement by pipe rotation in the transport efficiency of small cuttings is up to twice as large as the improvement in large cuttings transport. Compared with water, PAC solutions significantly improve smaller cuttings transport, while the transport of larger cuttings is only slightly enhanced.Mathematical modeling was performed to develop correlations for cuttings concentration and bed height in an annulus for field applications. Predictions from a three-layer model previously developed for larger cuttings were also compared with experimental results. Differences (up to 80%) indicate the need for improving the frequently used three-layer model by including correlations specifically developed for small cuttings to get a better design of extended reach drilling. This study is also useful for horizontal or high-angle well drilling and completion through sand reservoirs.
Streamline Assisted Ensemble Kalman Filter for Rapid and Continuous Reservoir Model Updating
Authors: Arroyo-Negrete Elkin , Devegowda Deepak , Datta-Gupta Akhil , Choe J. 
Published: December 2007

Abstract
The use of the ensemble Kalman filter (EnKF) appears to be a promising approach for data assimilation and assessment of uncertainties during reservoir characterization and performance forecasting. It provides a relatively straightforward approach to incorporating diverse data types including production and/or time-lapse seismic data. Unlike traditional sensitivity-based history matching methods, the EnKF relies on a cross-covariance matrix computed from an ensemble of reservoir models to relate reservoir properties to production data. For practical field applications, we need to keep the ensemble size small for computational efficiency. However, this leads to poor approximations of the cross-covariance matrix and loss of geologic realism through parameter overshoots, in particular by introducing localized patches of low and high permeabilities. This difficulty is compounded by the strong non-linearity of the multiphase history matching problem. Specifically, the updated parameter distribution tends to become Gaussian with a loss of connectivities of extreme values such as high permeability channels and low permeability barriers which are of special significance during reservoir characterization.
We propose a novel approach to overcome these limitations by conditioning the cross-covariance matrix using information gleaned from streamline trajectories. Our streamline-assisted EnKF is analogous to the conventional assisted history matching whereby the streamline trajectories are used to identify grid blocks contributing to the production response of a specific well. We then use these grid blocks only to compute the cross-covariance matrix and eliminate the influence of unrelated or distant observations and noisy calculations. We show that the streamline-assisted EnKF is an efficient and robust approach for history matching and continuous reservoir model updating. Our approach is general, suitable for non-Gaussian distribution and avoids much of the problems in traditional EnKF associated with instabilities, overshooting and the loss of geologic continuity during model updating. We illustrate the power and utility of our approach using both synthetic and field applications.