bluuebunny/crossref_metadata_2025_split huggingface dataset:
Utilizing Mini-DST for Formation Evaluation
Authors: Coelho A. C. D. , de Camargo C. , Kato E. T. , Legrand V. M. Q. F. 
Published: December 2007

Abstract
Well tests have been widely used for several decades in the oil industry for evaluation of the well productivity and formation damage, estimation of reservoir characteristics such as initial pressure, fluid type, effective permeability and identification of reservoir barriers or boundaries close to the wellbore. Based on the well test objectives and the regulatory constraints, several techniques may be applied: –a single wireline formation test to obtain a single-point static reservoir pressure, used for determining reservoir pressure gradients;–a wireline formation test to obtain the reservoir pressure and a reservoir fluid sample;–a mini-DST, using a wireline formation tester (WFT) to obtain some reservoir parameters in the near wellbore domain in addition to the fluid sample;–a vertical interference test (VIT) using a wireline formation tester with a vertical observation probe to estimate the near wellbore vertical transmissibility;–a closed chamber test to obtain reservoir parameters around the wellbore region while obtaining fluid samples;–a drill stem test (DST) to obtain average reservoir parameters, well productivity, PVT fluid samples and verify possible barriers and/or heterogeneities in the investigated region;–an interference test to check continuity and estimate average reservoir properties between wells;–an extended well test (EWT) to evaluate the production performance of well/reservoir in addition to other various objectives.
Due to the high costs involved in well test operations, especially in offshore exploration wells, the test type must be carefully chosen and properly designed in order to meet its required objectives at the lowest cost. The mini-DST is one of the cheapest options and may successfully be applied to obtain the reservoir static pressure and collect a reservoir fluid sample. In certain circumstances, the vertical and the horizontal permeabilities may be obtained. The WFT commercial tools may test the reservoir with a shorter investigation than the conventional DST, investigating the reservoir in the order of tens of meters. Regardless of the type of test adopted, all the operations must be conducted in accordance with strict environmental standards.
This work presents the mini-DSTs currently performed at Petrobras, indicating the operational and interpretation difficulties in order to highlight their actual applicability.
A Quantitative and Dynamic Risk Analysis Tool for Offshore Well Construction & Repair
Authors: Miura K. , Morooka C. K. , Mendes J. R. P. , Guilherme I. R. 
Published: December 2007

Abstract
The main concern of activities developed in oil & gas well construction is safety. But safety during the well construction process is not a trivial subject. During the well construction, the process transforms the context itself. Actual risk evaluation approaches focus on operational tasks on existent systems, like production plants, and they are based in static analyses of those. In other words, those approaches don't allow a dynamic analysis that evaluates the risk for each alteration of the context. The present paper presents a new methodology for both dynamic and quantitative risk analysis of well construction process. Moreover, it presents a prototype tool developed to support this methodology. With the use of this tool operational risk levels for each moment during well construction can be obtained, without a great effort of professional planning. By this approach, active barriers for each programmed activity can be quantified, given an initial situation. In this way, the dynamic analysis of amount of safety barriers during the well construction process can be easily obtained.
Beating the Marginal Well Performance in a Mature Field: San Francisco Field in Colombia
Authors: Suárez A. F. , Gaviria W. , Pavas J. , Frorup M. 
Published: December 2007

Abstract
Mature fields represent a special challenge in terms of drilling, because the net present value of the wells compared to the well investment diminishes with the degree of maturity. As the value diminishes, less and less time can be invested in reservoir studies to support field activities.Special workflows are therefore required to allow for a screening of potential infill drilling locations as well as a value assessment.
This paper presents the methodology and processes developed to define the infill drilling locations in the San Francisco field, as well as the execution and the results of the wells drilled, completed, and produced. These processes were developed after an unsuccessful drilling campaign in 2001 to 2002 and have helped arrest the field production decline.
The San Francisco field is an example of a mature field producing under a mature waterflooding project, at water cut greater than 90% owing to the level of depletion, an unfavorable mobility ratio, and high reservoir heterogeneity caused by the estuarine depositional environment.
A multidisciplinary team was set up to end with recommendations to ensure the coherence of the San Francisco Field development plan and to establish the 2003 and 2004 Drilling Campaigns. The workflow to identify drilling opportunities includes an analytical approach and a numerical simulation approach.
The analytical approach consisted of accounting for the well declines and the oil in place by sand and by area. This allowed a definition of reserves block by block and assessment of the possibility of production acceleration through drilling. A significant effort had to be given to the production allocation to support this workflow.
The numerical simulation approach consisted of accounting for the difference between the simulation model and the actual production observations. Being able to account for the difference between model and reality allowed determining how much effort is required to come up with a "reasonable" model, when do we stop to do the history matching, and how to adjust the production forecasts to account for the difference between model and reality.
Slickline With Fiber-Optic Distributed Temperature Monitoring for Water-Injection and Gas Lift Systems Optimization in Mexico
Authors: Brown G. , Carvalho V. , Wray A. , Sanchez A. , Gutierrez G. 
Published: December 2007

Abstract
Sensa tube with fiber optic distributed temperature sensing (DTS) has provided useful real time information for Pemex in various wells through thermal analysis of distributed temperature data. Four case studies are presented in this paper: the first case corresponds to a water injection profile survey at a Northern project. The other cases are related to gas lift optimization in the Northern and Southern Mexican regions.
As a part of the Pemex operated secondary recovery project in a Northern field, Fiber Optic Distributed Temperature Sensing technology has been used to monitor the water injection and warm-back temperature profiles across two perforated and fractured intervals, revealing the preferential flow into a one interval. The DTS thermal analysis provided important information to Pemex, which used the results as a guideline to take corrective action to increase the efficiency of their secondary oil recovery project. Pressure transient data was also collected to aid in the interpretation of the system using memory pressure gauges run on the fiber optic Sensa tube.
The remaining case studies will demonstrate DTS gas lift systems optimization projects. One of these cases shows an example of an efficient gas lift system, meaning no need of post work-over well intervention. The other two case studies reveal issues with the gas lift system design, which compromised the lift efficiency and consequently the well productivity.
Data acquisition using a portable fiber-optic Sensa tube unit has provided important information in a cost effective way. The DTS measurement provides a real-time and continuous temperature profile of the entire well, enabling the operator to monitor simultaneously all the gas lift valves, which is not possible to achieve with the usual time-consuming PLT surveys. Ultimately, the DTS monitoring has proven to be an efficient and reliable tool, saving the operator well intervention time and allowing immediate rectification of the issues observed.
Successful Application of Foamed Viscoelastic Surfactant-Based Acid
Authors: Mohammed S. K. , Nasr-El-Din H. A. , Erbil M. M. 
Published: December 2007

Abstract
A vertical well in a carbonate reservoir was damaged due to invasion of large volumes of water from an upper formation. Diagnostic work (temperature survey and chemical analysis of bailer samples) confirmed the communication between the upper formation and the reservoir. Obviously, invasion of large volumes of water can damage the well due to water blockage and the formation of viscous emulsions inside the formation. As a result of water invasion, the well ceased to flow. A workover was conducted on this well to eliminate the downhole communication, but still the well did not flow. Therefore, there was a need for an acid treatment to remove the damage and restore well productivity
The well was perforated after the workover in 112 ft perforated intervals. In addition, the carbonate reservoir is heterogeneous with several high permeability zones. For these reasons, acid placement and diversion were important. A viscoelastic-based acid system was selected to combine diversion and dissolving capabilities in one system. Moreover, the viscoelastic-based acid was foamed to enhance diversion and improve lifting of the spent acid following the treatment. Mutual solvent was added to the pre and post flushes to break the gel formed by the viscoelastic surfactant and help in removing the water blockage.
The treatment was applied using coiled tubing for better diversion in the wellbore. The treatment was very successful and resulted in major increases in oil production (more than 6,000 bbl/day). The well is still flowing at high rates nine months after the treatment. No significant change in water-cut was noted after the treatment.
This paper describes problem identification, fluid selection, and diversion. It will also discuss the first field application of foamed viscoelastic based-acid system.
VASPS Prototype in Marimba Field – Workover and Re-Start
Authors: Peixoto G. A. , Ribeiro G. A. S. , Barros P. R. A. , Meira M. A. , Barbosa T. M. 
Published: December 2007

Abstract
The Vertical Annular Separation and Pumping System (VASPS) represents an innovative concept for subsea two-phase (oil/gas) separation and pumping.A prototype of VASPS was installed inside a dummy well in 2001 at the Marimbá field, located in Campos Basin, Brazil.
The purpose of this paper is to present the second operational phase of this prototype, after a successful rig intervention to change a damaged Electrical Submersible Pump (ESP). This work also presents the improvements implemented in the control and supervision software of the system, designed to increase its reliability, and the overall results obtained after the second start-up.
Application of Intelligent Well Management System to Optimize Field Performance in Golfo San Jorge Basin — Argentina
Authors: Moyano H. , Fiore R. D. , Mazzola R. , Ponce C. , Ferrigno E. 
Published: December 2007

Abstract
This work is based on the experience obtained through the implementation of a well automation system at the Cerro Dragón Contract Area. The key operating device of the Intelligent Well Management System (IWMS) is the Intelligent Well Controller (IWC), which is an electronic device, with a new technology to obtain control of the well based on surface and downhole dynamometric registers, the result of associated parameters and calculations, and the behavior of the electric motor.
The purpose of this paper is to share our experience on the IWMS implementation and its contribution to: reduce the frequency of well interventions, accelerate the detection of well failures and decrease associated Downtime (DT), a quicker response detection at the waterflood affected wells, faster production optimization with new wells, save on energy demand, redesign the field operators' daily routine, define well selection criteria, and relocate current controllers. Taking advantage of the benefits of IWMS, we feel we are getting closer to excellence in the hydrocarbon producing field operations.
How Does Fluid Flow Affect Performance of CO2 Corrosion Inhibitors?
Authors: Gulbrandsen E. , Granå A. , Nisancioglu K. 
Published: December 2007

Abstract
The performance of three CO2 corrosion inhibitor products was tested in an impinging jet apparatus. The test conditions were 40 °C, 1 bar CO2, pH 5, 3 % NaCl. The O2 concentration was deliberately held within two different ranges: 2-4 ppb, and 10-30 ppb. The jet flow velocity was varied in the range 0.5-20 m/s. The flow velocity did not affect the inhibitor performance with the O2 concentration in the lower range. Flow dependent O2 corrosion was observed in the higher concentration range.
Matrix-Fracture Shape Factors and Multiphase-Flow Properties of Fractured Porous Media
Authors: Rangel-German E. R. , Kovscek A. R. 
Published: December 2007

Abstract
Experiments were performed using different fracture geometries, configurations, apertures, flow rates and two scales: pore- and core-scale. These were combined with analytical calculations and numerical reservoir simulation to examine the pattern, mode and extent of imbibition of water into permeable rock matrices. It is found that relative permeability functions for fractured rocks with impermeable matrices are different from those for fractured porous rocks. The experimental, analytical and numerical results, combined with previous studies, demonstrate that relative permeability functions for fractures not interacting with granular matrices are represented by X-type functions. Relative permeability functions for fractures interacting with porous matrices do not necessary exhibit X-type behavior. The shape of these functions is controlled by the rate of water advance through the fracture, that in turn is controlled by the fracture aperture, the injection flow rate, and the imbibition potential of the rock. As water advance through fractures determines, in part, matrix-fracture transfer, generalized shape factors are presented for both unsteady pressure and imbibition processes.
Analysis of Long-Term Behavior in Tight Gas Reservoirs: Case Histories
Authors: Arévalo-Villagrán J. A. , Jorge A. , Gutiérrez-Acosta T. , Martínez-Romero N. 
Published: December 2007

Abstract
This paper presents a production analysis catalogue to study and interpret the long-term production performance of tight gas reservoirs. The objectives of this paper are: to present physical scenarios that cause long-term linear flow in tight gas reservoirs, to present a catalogue of reliable, straightforward, and stepwise methodologies to analyze production data of tight gas wells in order to estimate reservoirs properties, OGIP, and movable gas reserves, to apply the production data analysis methodologies in actual tight gas wells, and to validate the results using numerical simulation. As a results we found that: 1. long-term flow in tight gas wells may be developed and controlled because the presence of natural fracturing in the reservoirs, 2. actual field data shows long-term transient flows with boundaries for years in a large number of wells that are producing from low permeability gas reservoirs, 3. long-term transient flow and short fracture half-length in various post hydraulic fractured wells suggest the need to develop tight gas field in a tighter spacing between wells, and finally 4. OGIP may be determines accurately without knowledge of porosity, drainage area, and thickness.
CO2 Corrosion Rate Prediction in Vertical Multiphase Flow
Authors: Adsani E. , Shirazi S. A. , Shadley J. R. , Rybicki E. F. 
Published: December 2007

Abstract
The mass transfer coefficient plays an important role in predicting corrosion rates. Using similarities between heat and mass transfer mechanisms, a mechanistic model is proposed to predict heat and mass transfer coefficients for two-phase flow in vertical pipes. The mechanistic model is evaluated by using water-air heat transfer experimental data obtained from the literature. The mechanistic model is also compared with commonly used empirical correlations. In comparison with available heat transfer correlations, the mechanistic model performs very well for vertical annular flow, bubbly flow and slug or intermittent flow that were considered. The mechanistic model is based on physics of two-phase flow and thus is expected to be more general than empirical correlations.
Delivering Environmental Assurance in a Global Organization
Authors: Sealy I. M. 
Published: December 2007

Proposal
Providing assurance to both external regulatory or best- practice standards, and to internal company standards presents a special set of challenges when an organization operates across a wide range of countries, business environments, and regulatory regimes. This paper describes a management system that has been developed, and implemented at five hundred sites in one hundred countries, over a one-year period to address this diverse set of assurance challenges.
A review in 2003 of the existing globally implemented environmental management system identified a number of requirements for improvement. These included a more robust system of assessment and assurance of external legal compliance; an improved internal audit and self-assessment process, and a clearer demonstration of alignment of the management system with established external best-practice standards.
Implementation of the new management system, together with a self-assessment and audit toolkit began in early 2004. The system was supported by a set of guideline and template documents that gave field users practical support for local implementation of the system. One of the Guidelines provided detailed instructions for the process of assessment of local regulatory requirements, and for the development of compliance procedures, at a site- or country-specific level in the organization.
An aggressive set of implementation objectives were set for the twelve-month period in which the system was globally implemented. Of the approximately five hundred sites that were required to use the system, 95% were required to conduct a self-assessment, and 60% were required to conduct an independent internal (company) audit by the end of 2004. Progress towards these objectives was measured via the established on-line QHSE database system. With a year's experience of system implementation, a review was conducted at the end of 2004 and was used to develop new objectives, and to identify requirements for further system improvements in 2005.
The Essence of Effective Integrity Management — People, Process and Plant
Authors: Ciaraldi S. W. 
Published: December 2007

Abstract
Effective integrity management (IM) is critical to the control of major accident hazards in oil and gas production operations. To achieve effective IM, it is necessary that an aware workforce deploy quality practices to sound facilities. An easy summary statement, but complex and difficult to achieve in practice. Based on the author's experiences with production operations on five continents, important people, process and plant requirements for acceptable IM are reviewed. Pitfalls encountered are also described, with examples of successful recovery noted.
People requirements start with leadership, accountability and competency, but go beyond to shared vision, passion to achieve and willingness to challenge the status quo when necessary. People are the first priority for IM, as they are often able to overcome shortcomings in process and plant; the reverse is generally not possible.
Hazard awareness, understanding and management is the cornerstone process for effective IM. If dangers are known and widely understood, effective means to mitigate and control can be devised, implemented and tracked. Other important processes include robust management of change (MOC), engineering practices, operating procedures, incident investigation processes, emergency response procedures and performance scorecarding.
IM plant requirements start with inherently safer design, quality procurement, fabrication and commissioning. These progress to practices for sustaining safety critical equipment including inspections, chemical treatments, monitoring and effective repair and maintenance programs. For the latter, testing and assurance around process safety protective systems is especially important. Finally, modifications to facilities to systematically reduce risk should not be forgotten, particularly over the long producing life of some assets. This may involve correcting existing deficiencies or the introduction of new technologies to do things better.
Computer Models Address Drilling Waste Management
Authors: Bloys J. B. , Fleming C. , Ivan C. , Piper W. A. 
Published: December 2007

Abstract
As part of the well planning process, the professional drilling engineer is confronted with the issue of drilling waste management. Frequently, the drilling engineer has little or no experience or training to deal with the variety of issues involved with drilled cuttings and waste drilling fluid disposal. Waste management is also becoming a larger part of total drilling costs and poses definite potential future liabilities to the operating company. One of the ways to fill this need without formal training is to provide the untrained engineer with computer software based on previous experiences. In this manner the untrained engineer can learn on-the-job without costly mistakes due to inexperience.
This objective of this paper is to discuss recently developed computer models that address drilling waste management issues. Some of the models discussed are: ■Solids control efficiency■Waste volume/mass generation■Pit sizing for onshore waste collection■Box needs for waste transportation■Technical feasibility of offshore disposal options■Liability associated with disposal options■Cost of offshore disposal options■Treatment requirements for disposal or re-use options■Land requirements for land application of drilled cuttings
While computer modeling is not new, the application of it to drilling waste management is certainly new. For instance, a bonus-malice system is used to evaluate liability and feasibility associated with offshore disposal options. This allows more realistic evaluation of disposal options. A second innovation is in the use of reverse-wave engineering. Applied to drilling waste disposal, the final disposal or re-use option is selected and treatments are suggested that meet the input and disposal criteria.
While the obvious advantage is to provide artificial intelligence to the user, there is another major advantage to software approaches to drilling waste management. The computer-based approach allows multiple, rapid evaluations of complex variables. The relationship between drilling parameters, waste handling, treatment, and disposal options can be better examined.