bluuebunny/crossref_metadata_2025 huggingface dataset:
Biostimulation Treatments of Hydrocarbon-Contaminated Soil in Semiarid Patagonia, Argentina
Authors: Haro P. A. , Perez J. D. , Alvarez A. F. , Silva R. A. , Alvarez H. M.
Published: December 2007

Bioremediation is considered an appropriate technology for decontamination of polluted natural environments. The successful application of bioremediation depends on appropriate hydrocarbon-degrading microorganisms and environmental conditions in situ. Las Heras is a place located in northwest Santa Cruz (Patagonia, Argentina) with a very intensive activity of oil industry. In this region the conditions most likely to limit hydrocarbon degradation include cold and fluctuating temperatures, low moisture contents, low nutrient levels and alkaline pH. In this work we describe three representative cases of biostimulation treatments (nutrients and water addition) applied to soils with different pollution states: Case A (1680 m3) exhibited high values of total petroleum hydrocarbons (TPH 33510 mg/kg); Case B (480 m3) showed high values of total petroleum hydrocarbons (TPH 27754 mg/kg) and polyaromatic hydrocarbons (PAH 1.64 μg/1 in lixiviate); and Case C (1680 m3) exhibited high PAH values (PAH 1.94 μg/l in lixiviate). The controlled addition of nitrogen and phosphorous sources and water increased bacterial counts of soil in all cases and resulted in a significant elimination of hydrocarbons: 32 % TPH in Case A after 7 months of treatment (from May to December 2005); 39 % TPH and 88 % PAH in Case B after 5 months (from October 2005 to February 2006) and 90 % of PAH after 3 months of treatment (from May 2005 to July 2005) were removed. In addition, we performed a comparative evaluation of natural attenuation, biostimulation and bioaugmentation (inoculation of bacterial strains) for bioremediation of PAH-contaminated soil in situ. Both, biostimulation and bioaugmentation promoted significant degradation (> 90 %) of PAH after 6 weeks of treatment, whereas attenuation resulted in a reduced degradation rate (67 %). In conclusion, this study suggests that autochthonous bacterial communities from semiarid soils in Patagonia have the potential to degrade hydrocarbons after amelioration of unfavorable environmental conditions.
Offshore LNG Technology: A Comparative Study of Conventional and Futuristic Salt-Cavern-Based LNG Receiving Terminals
Authors: Rai Sanchit
Published: December 2007

Tight oil supplies, escalating oil prices, and towering energy demands have led to the revival of natural gas. It is now deemed as the potential fuel of the near future. The trend now is toward supplying every cubic feet of the inland and offshore natural gas to the energy hungry consumers. LNG is recognized as the best form of gas transfer from remote inland and offshore fields to the consumers spread worldwide.

The natural gas is liquefied and shipped to distant receiving terminals. The chief technical features of a conventional terminal facility include LNG carrier mooring systems, unloading facilities, storing LNG in cryogenic storage tanks, LNG regasification systems and gas send out systems. The US has five such conventional terminals. The US is world's largest gas market with its gas demands expected to double by 2020. This is leading to the expansions and refurbishments of these conventional LNG receiving terminals with the construction of several more under various phases of planning and development. Recently, in the year 2005 Department of Energy (US), with 30 energy industry players successfully completed a research study on the concept of an offshore facility to moor LNG carriers, unload LNG and store it. This concept includes storing gas in salt-caverns. This technology is claimed to be highly cost effective, process efficient, with better delivery capacity and security. This idea is being realized by the construction of such a modern LNG receiving terminal in offshore Louisiana.

This paper aims to present a qualitative comparison between the conventional and the futuristic salt-cavern-based LNG receiving terminal. The comparison is based on the technology employment for these terminals.

Apart from the US, the LNG also holds immense promise to countries like Brazil, China, United Kingdom, Mexico, Germany and France. These countries are also contemplating LNG-facilities development and up gradation. This paper will be significantly important in understanding the various technological aspects of conventional and futuristic salt-cavern-based LNG receiving terminals on a comparative basis. This approach will be ultimately useful in understanding the technology-implementation for the development and modernization of the LNG receiving facilities in such countries.
The Effects of Fracture Cleanup on the Productivity of Gas Condensate Systems
Authors: Jamiolahmady M. , Ganesh D. , Sohrabi M. , Danesh A.
Published: December 2007

The performance of fracturing treatments has been an issue for over fifty years and considerable effort has been devoted to improve its prediction performance. However, the effect of cleanup in tight gas-condensate reservoirs where fracturing considered as the most common well stimulation technique, has not been fully investigated for these low IFT systems. The performance of cleanup operation heavily depends on the mobility, i.e., viscosity and relative permeability (kr), of fracturing fluid compared to those of gas and condensate. This determines the extent of invaded zone near the wellbore region and the ease with which fracturing fluid is removed during the back-flow operation.

In this work, measured values of permeability, single-phase inertial factor and kr of a propped fracture and those of a tight reservoir rock have been used to evaluate the performance of fracturing treatments. ECLIPSE 300 compositional reservoir simulator, which includes our in-house kr correlations accounting for coupling (i.e., the increase of kr as velocity increases and/or IFT decreases) and inertial (i.e., the reduction of kr as velocity increases) effects, was used to develop realistic fractured flow systems. A sensitivity analysis on the impact of different hydraulic fracturing fluid, fracture characteristics and reservoir fluids on the productivity of a single-well model were conducted resulting in some practical guidelines.

The results indicated that the performance of 300 cp high viscosity fracture fluid is better than that of 10 cp low viscosity fluid, due to a lower penetration depth. When kr of oil based fracturing fluid is improved, compared to that of water based, the back flow of fracturing fluid is facilitated especially for the 10 cp low viscosity fluid. Presnece of condensate facilitate the backflow of fluid, hence, cleanup efficiency is better for richer fluid systems.
Development, Verification and Application of a Screen Erosion Model
Authors: Cameron John , Jones Colin
Published: December 2007

Sand control completions are an increasingly more significant part of the overall well cost as hydrocarbon developments are pushed into ever more challenging reservoirs. Successful project economics and performance hinges on reducing the risk and consequences of failure to a practical minimum. Erosion is often identified as the failure mode when investigating sand screen failures – even though the true root cause is often procedural or operational in nature. Determining the cause of such failures is nearly always problematical when the equipment cannot be retrieved to surface. Erosion is therefore perceived to be a major risk in cased hole sand control completions and even in high rate open-hole and water injection wells. The key to controlling this risk is an understanding of the erosion rate and how it affects the sand retention properties of the selected screen.

The results of a comprehensive set of erosion tests have been used to develop a erosion model which predicts probable time to screen failure based on fluid type, flux rate, solids loading and size distribution. The model has been verified against a number of actual screen failures and also to predict failure times based on specific completion designs.
Characterizing the Complex Shaly Sand Oil Reservoirs in San Jorge Basin, Argentina, Using Advanced Magnetic Resonance Techniques
Authors: Fam Maged Y. , Vieiro Julio A.
Published: December 2007

Evaluating the complex clastic reservoirs in El Tordillo field of the San Jorge Basin in Argentina using conventional logs is greatly affected by variations in formation water salinity, texture, and lithology (primarily the amount of volcanic tuff material) combined with extreme changes in rock permeability and wide variations in oil viscosity. All of these factors affect most of the conventional logs responses in such a way that traditional log analysis methods may fail to provide proper results and consequently may not achieve appropriate forecasts. Such failures have been proven by the high degree of mismatch between conventional log analysis and test/production results.

To address uncertainties in conventional log evaluations, operators may resort to excessive well testing for reservoir characterization and production verification. However, well testing is known to be costly (considering the rig time and the frac jobs used). On the other hand, if the operator does not proceed with well testing, productive zones can be bypassed. That is why an effective log evaluation would be the optimum, cost effective method when it demonstrates agreement with production results.

The latest acquisition and interpretation techniques of the magnetic resonance imaging logs (MRIL) have demonstrated promising results in the complex shaly-sand reservoirs of El Tordillo field. The magnetic resonance imaging (MRI) technology run on wireline provides an in-situ evaluation of the reservoir properties vital for producibility predictions. The ability of MRI to estimate the type of fluid in terms of viscosity influences the selection and elimination of zones to be tested based on their mobilities. MRI also helps in properly preparing for the testing procedure by pre-identifying the type of hydrocarbon in a zone and by identifying its reservoir quality in terms of permeability and porosity. Thus, the MRI serves well when determining the need for well testing and in enhancing the effectiveness of any particular well test.

This article discusses the effectiveness of applying the MRI logging technology to the characterization of the shaly-sands of El Tordillo field in both the Comodoro Rivadavia and Mina El Carmen formations. It also argues for the value of MRI technology in minimizing the cost (and associated risk) of well testing by identifying best candidate zones for testing and by providing necessary "prior-to-testing" information on the fluid type (i.e., water, light oil, heavy oil or gas) present in a zone and rock properties, such as porosity and permeability.
Engineering Workflows for Production Surveillance and Optimization
Authors: Farid Kemal , José A. , Alvarez Cheo
Published: December 2007

This paper examines the growing need for workflow management in the upstream production industry. Workflow management is the management and improvement of data and activities through specific business, scientific, or engineering processes. This paper discusses the application of workflow management to upstream production surveillance using software that can integrate large data volumes with multiple engineering tools.

Engineering workflows can provide new and improved analytical capabilities that are applicable to a wide range of tasks, including field development planning, production deferment tracking, and assisted model creation, among many others. Effective workflow management is associated with multiple benefits, including knowledge retention when older employees leave the workforce, knowledge transfer, and process automation that results in the more cost effective management of production assets. Engineering workflows can automate field surveillance by combining production models with access to multiple data sources.

As an example, we present the use of a model-based surveillance-by-exception workflow to produce timely, actionable data for proactive field management. This worfklow also serves as an excellent model of how the integration of data, tools, and processes can be better achieved through workflows.
Gas Productivity Enhancement by Wettability Alteration of Gas-Condensate Reservoirs
Authors: Al-Anazi Hamoud A. , Xiao J. J. , Al-Eidan Ahmed A. , Buhidma Ismail M. , Ahmed Mahbub S. , Al-Faifi Mohammad G. , Assiri Wisam J.
Published: December 2007

Gas condensate reservoirs experience significant productivity losses as reservoir pressure drops below the dewpoint due to condensate accumulation and the subsequent reduction in gas relative permeability. One potential way to overcome this problem is to alter reservoir wettability to gas-wetting to reduce condensate accumulation in the near-wellbore and maintain high productivity. The aim of this study was to evaluate the effectiveness of various chemical treatments in altering wettability of gas-condensate reservoirs from liquid wetting to intermediate gas wetting. Coreflood experiments were conducted on carbonate and sandstone reservoir cores and Berea cores at simulated reservoir conditions. Several chemicals (fluorochemical and silane) were screened in this study to determine their capability in removing the trapped condensate from cores, enhancing gas relative permeability, and delaying condensate accumulation. The results of coreflood tests showed that the effectiveness of fluorochemical surfactant is affected by treatment volume, aging time, core permeability and temperature. Sandstone cores treated with 1.25 wt% silane chemical showed repellency to liquids (water and condensate) and an enhancement (up to 42%) in gas relative permeability. It was found that core permeability plays a role in wettability alteration agents' effectiveness. Wettability tests showed that contact angle on treated cores is 116° for water and 114° for condensate, indicating wettability alteration from liquid to intermediate gas wetting. Environmental Scanning Electron Microscope (ESEM) analysis performed on silanes-treated cores gave a conclusive evidence of wettability alteration at the pore scale.
Case History: Application of CHI Modeling® Using Pulsed Neutron To Create Pseudo-Openhole Logs in Highly Deviated Wells Using Special Techniques for Logging and Perforating in Veracruz, Mexico
Authors: Reed Skip , Torne Juan Pablo , Pacheco Erick , Augusto Lara , Casillas Zenon , Palacios Cesar , Riaño Juan Manuel , Corral Aguirre Alejandro , Casares Martin , Simon Jose D. , Arteaga Rafael
Published: December 2007

The Veracruz basin, located in eastern Mexico, has sometimes been very difficult to evaluate with openhole wireline tools because over-pressured gas formations present a problem when trying to reach a balanced borehole condition. One of the fields was planned for development using nearly horizontal wells to maximize production, but acquiring openhole logs in these wells has proven to be difficult.

Well A-21 is the first highly horizontal well to be completed using only LWD resistivity data in the nearly horizontal section. To assist in the evaluation after the well was completely drilled and cased, a pulsed neutron tool was logged across the entire well using a tractor device to reach the total depth of the well. An evaluation model for the A field was then developed using the CHI (cased hole interpretation) modeling program, by using the openhole resistivity and porosity data acquired in the vertical A-1 well, combined with the cased hole pulsed neutron data acquired across the same interval. Pseudo resistivity and porosity logs were then created for the A-21 well using only the pulsed neutron data acquired across the nearly horizontal section of the well, based on the Chi Model developed for the field. The pseudo resistivity was then compared to the LWD resistivity data acquired in the A-21 well. Next, the interpretation was completed by defining the optimum perforating interval for the reservoir conditions and the mechanical condition of the well. After evaluating the interpretation, the On-Balance perforating technique using coiled tubing was decided upon as the optimum technique to perforate the A-21 well, to minimize reservoir damage. This paper will present the procedures used to evaluate and complete the A-21 and the A-31 wells, as well as a comparison of the CHI Modeling pseudo resistivity with the LWD resistivity measurement.

The use of pulsed neutron logs to acquire pseudo openhole data is shown to be a valid alternative when drilling conditions do not permit normal data acquisition in openhole. The integration of the data obtained, along with applied reservoir geomechanics, for perforating design and production planning is shown to be a valid alternative to maximize production, and to prevent sanding and completion problems while reducing costs.
How To Select PDC Bit for Optimal Drilling Performance
Authors: Nygaard R. , Hareland G.
Published: December 2007

Selecting bit when you have multiple bit vendors giving their proposal can be a challenge for the operator. To justify the bit selection can be hard for the drilling engineer in a multiple vendor situation. The purpose of this paper is to show a systematic approach on how to select PDC bit based on quantitative measure by using a simple scorecard. When the drilling organization has agreed on the overall drilling objective for the well a scorecard is used as decision criteria for selecting bits. To quantify the input for each bit a drilling simulator was used. The simulator can, based on a rock strength prognosis for a well, predict the rate of penetration and bit wear for each bit based on the bit design. For other criteria which are more difficult to obtain e.g. ability to create dog leg a qualitative ranking was used. In the two field examples shown from the North Sea the method has worked well to give a reliable and transparent bit selection method. Using a scorecard also reduced the ambiguity among the bit company representatives on how the selection process was done.
Improved Drilling-Process Control Through Continuous Particle and Cuttings Monitoring
Authors: Omland T. H. , Saasen A. , Taugbøl K. , Dahl B. , Jørgensen T. , Reinholt F. , Scholz N. , Ekrene S. , Villard E. , Amundsen P. A. , Amundsen H. E. F. , Fries M. , Steele A.
Published: December 2007

Major advancements have been made in the past decades to determine the effects from particle additions to drilling fluids. These additions affect wellbore stability, hole cleaning, sag stability, formation damage and back-production capabilities. Furthermore, optimum drilling fluid performance is strongly dependent on knowing the properties of the formation such that correct selections of drilling fluid additives can be made. Likewise, it is important to know if produced solids are drilled cuttings or cavings originating from unstable holes.

In field applications, there has been reluctance towards trusting solids control equipment as the only method for controlling the particle size distribution (PSD) and particle content of the drilling fluid system, since no real-time monitoring equipment has been available to produce the necessary measurements. The present paper describes a technique based on image analysis, which makes it possible to obtain such information in real-time. The method also provides valuable information for characterizing drilled cuttings, creating the basis for caving logs. A method for obtaining mineralogical data from the formation by analyzing the drilled cuttings by using Raman spectroscopy is also described. Field tests and laboratory studies demonstrate the potential of the techniques for improved drilling process control by continuously monitoring the particles in the system while drilling. Some of the elements in a drilling fluid process which are affected by the presence of particles are also described.
A New Tool for Exploration and Appraisal—Formation Damage Evaluation
Authors: Byrne Michael , Patey Ian , Green Justin
Published: December 2007

Formation Damage can be defined as any near wellbore alteration that affects permeability due to well operations. Use of any tool(s) to avoid or rectify formation damage may be helpful in terms of reducing costs or improving hydrocarbon recovery. These tools may either indicate or predict the changes in near wellbore permeability, and may identify the cause and suggest alternative well operations and/or specific remedial treatments to improve hydrocarbon recovery. A new tool has been identified to realise and help unlock the hidden potential of marginal fields at the exploration and appraisal stage. This is a tool based on multi-criteria decision analysis that combines the use of pre-existing geological and reservoir conditions core flood laboratory analysis, which predominantly compares datasets before and after simulations of well operations to enhance formation damage evaluation and assist in making cost benefit descisions. Existing geological and well data can be combined with a comprehensive formation laboratory study, to effectively create a new tool which, based upon multi-criteria decision analysis, can assist in making cost benefit decisions.

The majority of formation damage laboratory testing is performed during field development in order to determine the least damaging drilling, completion and injection fluids and procedures. This analysis has now become routine and is part of field development planning for most major operators. Formation damage evaluation should also be conducted at other times in the life of a field or well. The reservoir can be damaged or can suffer damage mechanisms throughout its exploration, appraisal and development history. By understanding damage from the day the first drill-bit penetrates the field we can develop a greater understanding of reservoir potential. Full simulation of drilling, completion and production of exploration and appraisal wells can unlock hidden potential in marginal fields.

Examples of the impact of formation damage on well performance and some examples of formation damage investigation and remediation will be discussed. Specific examples of how formation damage has been used to re-value potential of marginal discoveries and has led to successful development will be presented.
HPWBM as a Technical Alternative to Drill Challenging Wells Project: Lessons Learned in Deepwater Brazil
Authors: Ramirez Mario A , Moura Eliabe , Luna Edgar , Aragao Atila , Taira Helio
Published: December 2007

Traditionally, Non-Aqueous Fluids (NAF) have been used by a major operator to drill challenging wells in the Campos Basin, Brazil. Significant advances in water based drilling fluid design in the recent years have allowed water-based drilling fluid performance to approach that of NAF. Exploration in the new frontiers and optimized development well projects in deepwater Brazil have required a different approach regarding drilling fluid design due long step outs, difficult well trajectory, and the possibility of drilling horizontal wells in one step, thus avoiding intermediate casing strings. Although NAF are an ideal candidate for those applications, environmental concerns and logistic demands are still an issue and alternatives should be considered.

HPWBM has been applied to replace NAF in some applications in deepwater and ultra deepwater (UDW) in the Campos Basin. This novel technology has been successfully applied to drill in UDW scenarios, reactive clays, dispersive shale, naturally micro fractured formation and horizontal wells. HPWBM characteristics are developed with: 1) A new generation of encapsulation polymers; 2) The use of amine chemistry to provide clay stability; 3) The application of novel sealing polymer for shale stability; and 4) Excellent mud lubricity characteristics.

The lessons learned, as supported by case histories and lab data have contributed to system modifications which have improved performance. This work has also identified attributes needed to complete a drilling fluid design for the difficult wells to be drilled in the new exploration and development areas. The evolution of HPWBM drilling fluid design will be discussed along with how decisions were made.
Managing Risk and Uncertainty in the Visualization of Production Scenarios
Authors: Saputelli L. , Mijares G. , Rodriguez J. A. , Sankaran S. , Garibaldi L. , Revana K.
Published: December 2007

Field development decisions must be made despite uncertainties of well performance, subsurface response, equipment failure rate, and downstream demands. The heterogeneity of information and complexity of current hydrocarbon assets implies an iterative approach to identify opportunities, which requires risk and uncertainty management. To accomplish such a challenging goal, it is necessary to estimate requirements for surface facilities while considering both reservoir uncertainties and multiple development scenarios, and their link to the economic model.

Optimizing production operations may involve identifying opportunities for production increase from reservoir, wells, and surface equipment with the minimum effort. In addition, to make robust planning

This paper presents methodologies, technology applications and case-studies for managing risk and uncertainties in the visualization of production scenarios. They are shown examples of multiple reservoir forecasts with wells and surface facilities network models and operational issues, such as well performance, subsurface response, equipment failure rate, and downstream demands.

We show several integration procedures for handling reservoir production uncertainty, well performance, drilling schedule compliance, workover success, and varying surface facility variables, such as availability, uptime, and capacities. The examples shown in this paper permits the visualization of a more realistic short-term asset performance while minimizing requirements in the long-term, minimizing risk and manging uncertainties.
Leverage Knowledge-Management Tools To Better Understand and Meet the Needs of the Industry
Authors: Paylow K. , Hickman A. , Liu S. , Guidry A. , Zappa D.
Published: December 2007

To meet the long-term technology and performance needs of the upstream industry, the present and future market must first be understood and then acted upon. A collaborative knowledge management (KM) system complements other market assessment tools by harnessing the collective capability and experience of an organization's employees to more effectively identify, communicate and act on customer needs, market knowledge and potential solutions.

While many companies' KM efforts are focused on technical problem solving and/or employee development, a KM system can also be used to develop better organizational and individual understanding of, and more importantly, adaptation to the market. Any employee can initiate or participate in collaborative communication to actively share and discuss customer needs, competitor activities, new technology applications and successes. Any employee can submit ideas for new or improved products to meet their local market needs. Where appropriate, these ideas are collaboratively reviewed, improved and validated through KM.

We use our KM system to better understand the market and drive innovation. Examples demonstrate the use of collaborative discussion to share market intelligence, clarify market assumptions, harness the ‘wisdom of the crowd’ in collecting and validating new product/service ideas and transfer technology.

KM tools and collaborative activity show promising value in improving market understanding and driving technology innovation. Halliburton broadly defines knowledge management as a systematic approach to getting the right information to the right people at the right time. Often the ‘right information’ pertains to market needs, new ideas or new technology.
Mastering Real-Time Data Quality Control—How To Measure and Manage the Quality of (Rig) Sensor Data
Authors: Mathis W. , Thonhauser G.
Published: December 2007

The amount of data collected in the information age has grown to amounts barely manageable. Currently available technologies are already capable of transmitting the readings of any sensor to worldwide locations at high frequencies and with nearly no time delay. With an ever-increasing flow of data, the need for criteria to measure and evaluate data quality are more pressing than ever, as this data forms the basis for many critical business decisions. This paper addresses these problems and shows essential steps to a successful data and quality management strategy:

Quality control and improvement Data quality benchmarking Accessibility of controlled data

Simple but very effective signal processing algorithms are presented to ensure that the data is in the right value range, outliers are removed and missing values are substituted where possible. More complex control instances may not be able to correct data completely by automation. Here the human expert is still necessary for corrections. To minimize the work for engineers, a processing engine produces smart alarms whenever an automated data correction is not possible. If no correction is possible at all, the questionable portion of the data must be flagged invalid, or even be deleted to prevent misuse and wrong conclusions. This may be dependent on the application; so good data management is essential to provide a minimum standard for each individual case.

The final step is to publish and present the data at the correct level of detail to different parts of the corporation. Key in this procedure is that every individual has easy and fast access to the data for their decision-making. In this context, the appropriate resolution, as well as the most efficient use of data processing time, is of critical interest. A unique solution to browse large volumes of drilling data is presented.
The Use of Multilateral Technology in an Environmentally Sensitive Area: The Val d'Agri Field, Italy
Authors: Caproni Cristiano , Johnstone John , Cavallaro Giorgio
Published: December 2007

Current trends in the oil and gas industry are focused more in operational efficiency, production optimization, value, and environmental effects than ever before. The industry actively pursues technologies and techniques that offer improvement in these areas, which explains the increased interest in multilateral well designs. In highly sensitive areas, such as national parks and areas of geographical sensitivity, it has become extremely difficult to obtain permits to prepare well sites if this preparation requires the removal of forestry, permanent scarring of the landscape, or disturbances to the wildlife or to the people who live and work in the area.

The Val d'Agri field in southern Italy is located within the boundaries of the Basilicata National Park. Consequently, Eni and its partners were challenged with reaching production targets while minimizing land disturbances. Eni evaluated and implemented multilateral technology to help meet the objectives.

The forward thinking of Eni led the company to pre-install orientation devices in the casing string during the original construction of the well. This action made it possibile to perform multilateral solutions if/when needed, such as the TAML Level 5 implemented on well Agri-1 or B.

The first orientation devices to be used were installed in well Cerro Falcone 3X or A in 2000 to construct a TAML Level 2 junction with re-entry capabilities through the completion. In 2003, the same technology was used on Agri-1 or A, where the orientation devices were installed in the 7-in. and 9-5/8-in. casings. When well Agri-1 or A was put on production, the produced fluid was found to be much more corrosive than expected. The well had to be shut in because the metallurgy of the equipment in the well was not suitable for the corrosivity of the produced fluid.

Eni and Halliburton formed a team to evaluate the situation and design a suitable solution: to exit from the 9 5/8-in. orientation device and drill a secondary lateral. This secondary lateral required a TAML Level 5 junction with an Incoloy 925 completion to isolate the junction and to provide through-tubing access to all bores, including the existing Agri-1 or A.

This paper focuses on the methodology and value this technology brought in the achievement of planned production targets.
Optimization of Stimulation Treatments in Medium-Permeability Gas/Condensate Reservoirs Using Real-Time Downhole Data Acquisition With Novel Technology of Permanent Sensors
Authors: Santillan Arturo , Inda Antonio , Steffani Octavio
Published: December 2007

Development of light-oil fields in Mexico is part of a strategic program to increase overall production in Mexico. Among the light-oil fields, operators have gas condensate carbonate reservoirs with medium permeabilities ranging from 3 to 10 md, with very high drawdowns. The initial development concern was how to make them produce above the bubble point. The first thought was to fracture the intervals to reduce the drawdown, but the permeability values from well tests made matrix stimulation appear acceptable. Some believe that with permeabilities in the 3 to 10 md range, fluid-loss issues may prevent reaching fracture pressure. In that case, a matrix treatment may be used, thus avoiding a more expensive hydraulic-fracture treatment.

However, step-rate test (SRT) results were unclear, so doubt remained. In three cases, permanent downhole sensors were available, and minifrac and fall-off analyses with downhole data were possible. Observation of the flow regimes in the data established a comparison of planned flow periods before and after the tests and frac jobs. If this data is used to help optimize treatment, applying frac treatments will be the best choice, and the investment will be justified. It was also observed that lower injection rates must be applied during the SRTs, starting from 0.5 bbl/min.

The operator concluded that "gray zone" candidate wells with medium permeabilities can benefit from matrix treatments and fracture treatments.

Post-fracture evaluation shows that drawdown matches very closely to the flow prediction, and this kind of reservoir can be produced above saturation points.

In this paper, three successful case histories are discussed in detail.
A Performance Review of 14 Horizontal Wells in Baronia Field After 12 Years of Production
Authors: Jadid Maharon , Mustapah Mohd Fahmi
Published: December 2007

As a production optimization strategy in a brown field, horizontal wells were introduced in the Baronia Field some 22 years after the first production in 1972. With the help of a reservoir simulation model, the performances of typical horizontal wells were simulated to justify drilling of 14 horizontal wells in the infill drilling campaign of 1994. The simulation results indicated a substantial increase in the recovery factor with horizontal wells compared to conventional wells due to delays in gas or water breakthrough. In addition, with the better drainage coverage, less wells were needed to drain the stratified reservoirs. During these early days various types of horizontal completions were introduced to compare the effectiveness of the various well constructions.

This paper presents a review on the actual performance of the 14 horizontal wells in Baronia based on the past 12 years of production history. This review is highly desirable and timely, firstly in verifying the initial reservoir simulation results in order to improve and optimize on the horizontal well technology applications in future wells. The second objective is to determine the productivity and efficiency of different types of horizontal well completions that were applied in Baronia i.e. cased hole and perforated, open hole with pre-perforated liner and open hole with pre-packed screen.

As expected, the performance review indicated that horizontal well performance is much more superior than the performance of the normal conventional deviated well. It is also clearly shown that of the different horizontal well completion types, the open hole completion with pre-perforated liner or pre-packed screen yeilds a better productivity compared to cased and perforated completion. In addition, the horizontal borehole size (i.e. the size of the liner) has an impact on the productivity. The results confirmed that the biggest liner size i.e. 7 inch or 7-1/2 inch liner gave the best productivity.

The results of this review including the various advancements in the horizontal well technology will be adapted as a general reference for the future horizontal well construction and application in PETRONAS Carigali fields.
PIMS (SDIP)—Safe Driving Integrated Process: An Integral Vision To Solve an Old Problem
Authors: Martín Carlos M.
Published: December 2007

Description

Serious consequences of failures that occur while driving vehicles having to do with our industry are widely known. Movement of equipment has a more than considerable specific weight within the set of operations.

This work aims to show the importance of an integrated vision of the problem in search of its solution, as well as attainable improvements through this one in Journey Management and Driving.

Application

Because it has been detected that faults in driving oil industry vehicles are mainly associated with risky behavior or driver's decision errors, BJ has been forced to reorientate its programs: we have stopped talking about defensive driving and management tools, to start talking about a Safe Driving Integrated Process, composed by key elements related to each other. If any of these elements is weak, the process itself is bound to fail.

Results, Observations, Conclusions

Experience demonstrates that application of isolated specific management tools implemented up to now, has not given the expected results.

After 2 years of the implementation of the Safe Driving Integrated Process, key indicators trend shows improvement: lower incident frequency and severity.

The elements that compose the system are: A defined Driving and Journey Management Policy: it establishes the suitable frame of leadership, from which the whole process management is developed.Knowledge: a driver applying safe driving techniques to develop his abilities, without solid knowledge, is not possible.Verification of skills and abilities: fundamental part for the process assurance.Journey Management: it aims to obtain that a driver knows how to identify and to control the hazards and risks associated to a trip - including himself and his equipment- but mainly to make him realize how to make the proper decision. It includes the emergency response actions.Monitoring and follow up of behavior: to allow preventive and corrective actions to be taken so as to align the driving process to the behavior based safety program.

Significance of Subject Matter

The effective and successful application of this process results in having less fatalities, personal injuries and property damage in our industry and areas of influence.
Improved Frac and Pack Job Design and Execution in Baram Field—A Case History
Authors: Arfie Mezlul , Jadid Maharon , Samsudin Norsamsuriya , Azer Alfred , Ali Razien
Published: December 2007

Baram Delta Field is a mature hydrocarbon-producing field in east Malaysia. The reservoirs are predominantly friable and unconsolidated. Downhole sand-exclusion systems are required to help ensure prolonged well productivity.

Historically, most wells were completed with internal gravel packs (IGP) and high-rate water packs (HRWP) with good success rates. However, there were concerns of inconsistent final completion skins that could result in wells not producing to full potential.

In an effort to improve and optimize sand-control techniques, the frac-pack technique was introduced to achieve not only sand exclusion but also provide additional reservoir stimulation.

This paper describes the transition of an idea from sand control only to optimizing production through reservoir stimulation. A reservoir selection process for applicable frac-pack treatments is also reviewed.

Because this technique was relatively new to this field, fracture design analysis was thoroughly reviewed before the actual application in an effort to ensure maximum benefit from the treatment.

This paper is intended to systematically translate and interpret the field data acquired, with the aim of improving the quality of the job, the fluid design, and pumping diagnostic stage to achieve TSO (tip screenout) fracs.

It is expected that variability in skin after frac-pack treatments can be minimized and the best productivity can be achieved by having an optimized fluid design along with standardized pumping diagnostic and TSO design technique.

The well performance from these frac-pack wells was also evaluated to quantify the benefit of these improved techniques.
Cement Design To Optimize Production in a Highly Active Waterdrive Reservoir
Authors: Capacho Carlos , Baquero Felipe , Ravi Kris , Vela Jose
Published: December 2007

This paper describes the improvement in well production from using advanced well-construction techniques compared to conventional techniques. The advanced technique uses an engineering approach including finite element analysis (FEA), specialized erodability testing, rock mechanics lab testing, and conformance reservoir simulation predictions.

In a highly permeable and very mobile water-drive environment where natural hydraulic seal is practically non-existent, an effective cement sheath imposes a very good mechanical seal to shut the water influx. In this case, the cement sheath is not only a well-construction or pipe-stability issue, it is a final or well-termination product for enhancing well life or last-recovery production. The FEA analysis studies the mechanical interaction among the formation, cement sheath, and casing while applying different stresses on the system. Pressure and temperature changes inside the casing during the life of the well affect the behavior from the cement sheath. To address the performance from the cement system design, the well history for water production requires review. Production and simulated data from reservoir simulators are compared to determine if water production is as expected or not. Conformance reservoir simulators give a good comprehensive criterion to predict water behavior in the reservoir and predict at earlier stages when water will affect well productivity.

In the study presented in this paper, three advanced solutions were applied to address an optimization in a highly active water-drive reservoir as: (1) spacer efficiency study, (2) cement-sheath characterization through measured mechanical properties/FEA analysis, and (3) use of conformance simulators to determine the productive capacity of the well. Results are compared with the real production data to determine whether this engineering design improved well productivity.

Results of using all new practices were evaluated by CBL logs and production; production results were close to the expected, with low water cut. Yuralpa Field can become uneconomical if cement sheath quality and reservoir standoff to oil-water contact are not suitable.
Production Data Analysis of CBM Wells
Authors: Clarkson C. R. , Jordan C. L. , Gierhart R. R. , Seidle J. P.
Published: December 2007

Recent advances in production data analysis (PDA) techniques have greatly assisted engineers in extracting meaningful reservoir and stimulation information from well production and flowing pressure data. Application of these techniques to coalbed methane (CBM) reservoirs requires that the unique coal storage and transport properties be accounted for. In recent work, the authors and others have demonstrated how new techniques such as the flowing material balance (FMB) and production type-curves may be adapted to account for CBM storage mechanisms (i.e. adsorption), but to date the focus has been on relatively simple CBM reservoir behavior. Although adaptations of PDA to include more complex CBM reservoir characteristics were introduced, the focus of the current work is advancement of modern PDA techniques to incorporate reservoir behavior such as single-phase flow of water in undersaturated reservoirs, two-phase (gas+water) flow in saturated reservoirs, effective permeability changes during depletion, and changing gas composition due to relative adsorption. Specifically, the FMB technique is modified in this work to include several complex CBM reservoir characteristics. FMB can be a powerful diagnostic technique when relative and absolute permeability changes are apparent during depletion. Several synthetic and field examples are given to demonstrate how FMB, type-curve analysis and analytical simulation can be used in parallel to provide a particularly useful data analysis tool.

The adapted PDA techniques used in this work make use of the pseudotime and pseudopressure concepts, modified to account for CBM reservoir behavior, to linearize the (constant-rate) diffusivity equation for CBM. Material balance pseudotime was used to account for variable operating conditions. These techniques were used successfully to extract quantitative reservoir information from single- and two-phase CBM simulated and field production and pressure data. The techniques for two-phase CBM require further evaluation, however.

Several key assumptions were used in deriving the PDA techniques including (but not limited to) instantaneous desorption (small sorption times) and single-layer behavior. Although the former is not considered a serious limitation, as most commercial reservoirs analyzed to date by the authors have exhibited single-porosity behavior during production, the latter may be quite important for some producing fields. PDA of multi-layered CBM reservoirs will be discussed at length in a future paper.