bluuebunny/crossref_metadata_2025_split huggingface dataset:
Frequency Dispersion Effects on LWD Propagation Resistivity Measurements
Authors: Haugland S. M. 
Published: December 2007

Abstract
Measurements sensitive to the resistivity of earth formations acquired during and after the drilling of oil and gas wells can be subject to frequency dispersion effects. The frequency range of interest in this paper is from practically zero to two million cycles per second. The most common measurements are wireline induction (10 – 100 kHz) and LWD propagation resistivity (0.4 MHz – 2 MHz).
Methods suggested in the literature to analyze data subject to this effect range from simply assuming Rt is the deep 2 MHz attenuation resistivity to applying a CRIM (complex refractive index method) or other mixing law such as the Hanai-Bruggeman model. No physical basis was given by the authors who recommend using the 2 MHz attenuation resistivity. In addition, the attenuation resistivity depends on a dielectric assumption which varies between service companies as does the spacing for the deep measurement. On the other hand, the mixing models appear to be impractical because they depend on material properties such as the formation fluid content, pore microstructure, clay content, grain size, porosity, tortuosity, etc.
Published log examples consistently indicate that dispersion effects occur in formations with anomalously large apparent dielectric constants. By definition, a medium with a large apparent dielectric constant is readily electrically polarized. This paper applies the accepted knowledge that polarization effects over the frequency range of interest tend to be dominated by interfacial relaxation within the rock-pore system. On this basis, an equivalent electric circuit model is used to determine the low frequency limit for the conductivity and dielectric constant based on LWD propagation measurements.
Log examples will be presented where the algorithm is applied to data from a dual frequency LWD propagation resistivity tool with three fully compensated spacings. As expected, the low frequency limit conductivity from data at each spacing is shown to be higher than the dielectric-independent resistivity values used to compute the parameters of the circuit model. The low frequency limit dielectric constant is also higher than the apparent dielectric constants used in computing circuit parameters.
The algorithm and its underlying theory are discussed in detail. The possibility of applying it to anisotropic and inhomogeneous cases is also discussed.
Behavior-Based Safety Implementation in Thailand: Factors Critical to Success
Authors: Whitney P. , Stanley A. 
Published: December 2007

Abstract
A systems-oriented, behavior-based safety (BBS) process was initiated during 2004 in Songkhla, Thailand. Songkhla was selected as an implementation site because of their willingness to be involved, good safety performance, and high expectations for success. Being a systems oriented approach, the process included elements for team development, behavior observation and feedback, data recording and analysis, improvement action planning, and sustainability.
Factors critical to the successful implementation were: management leadership, communication, and employee ownership and participation. Examples are given showing how these different factors were applied effectively, including: how management showed leadership, the types and frequencies of communications, how the employee team was organized, and how employees were motivated to participate. To monitor progress, it was important to link these factors to meaningful performance measures.
Historical performance was measured primarily on injury rates. While useful, lagging indicators emphasize the negative aspect of performance, and when rates are low, it is difficult to differentiate true improvement from statistical noise. For BBS, several leading indicator performance measures were introduced. Performance indicators other than injury rate were needed for two reasons: (1) injury rates before the BBS process began were low, and (2) the BBS process was designed to be proactive. Plotting process performance measures over time indicates improvement but there are limitations to the measures.
Based on employee and management feedback, and performance indicators, the program has been successful. Halliburton implemented over 20 BBS processes in several different countries before the Thailand implementation. The critical success factors are broadly applicable although effective application varies with culture and local environment.
Uncertainty and Value in Integrated Asset Modelling
Authors: Crerar A. , Robertson A. 
Published: December 2007

Abstract
The paper will illustrate the application of asset-scale modelling and the benefits thereof, including an analysis of the effect of quantifiable risk on development strategy selection.
While integration asset modelling (IAM) is not of itself a novel topic, practical applications of the technique applied from sub-surface calculations through to commercial/financial analysis are nevertheless uncommon and those including a rigorous treatment of uncertainty still rarer. Included in the paper will be a brief analysis of both the benefits of IAM and suggestions on why it is perhaps not more widely applied.
The main body of the paper, however, will cover two case studies - descriptions of projects carried out using the RAVE (Risk And Value Engineering) IAM software. The first case study will be based upon the Brae asset, operated by Marathon Oil UK. The Brae asset is complex, both technically and commercially, and represents a huge infrastructural investment in the CNS. The paper will illustrate the means by which IAM was used to "see through" this complexity to assist in the forward strategic planning of the asset.
The second case study will describe the development of a reserve as a third party tie back to an existing host platform. Use of the approach in this case allowed rapid, value-based analysis of competing development alternatives (such as host selection, artificial lift techniques and well count) including the sub-surface uncertainty inherent in pre-FEED development studies.
From the case studies presented here and numerous similar projects, the authors will present the conclusions that risk- inclusive integrated asset modelling is both feasible and valuable in marginal and mature environments.
Real-Time Information to the Engineer’s Desktop - How Murphy E&P Improved Production Management
Authors: Oberwinker C. , Holland J. , Mayfield D. , Dixon D. 
Published: December 2007

Abstract
Real Time is the new buzz in the upstream petroleum industry. So far, operators have been the main users of data measured at second or minute time increments to manage wells and keep them on production. Engineers usually see only a sub-set of the data - the daily production volumes and rates along with a few select- gauge pressure and temperature readings. The limited data means that they only see the result - the production volumes - and not the reason for a certain production parameter - e.g. choke size, pressures, temperatures.
SCADA - Supervisory Control And Data Acquisition - is the system, which connects to the gauges, collects the measured data and stores it in a database. Operators on the platform have direct access to this data and use them to control the wells. If the engineers see this data at all, they usually get them through a web browser interface and in a format they cannot directly use for their analysis. One of the reasons for this is that many SCADA providers come from other industries where the needs are quite different and the network resources are much more substantial.
This paper will introduce a new concept of integrating high frequency data up to the management level. Each level of the organization sees as much as they need or want to see of the high frequency data. The engineers have exactly the same view as the operators at the platform - at the same time. This might seem to be a problem at the first, but in the long term, it is an empowerment of the operators and brings engineers and operators closer together working as a team to manage the wells. The data also allows management to monitor the oil- and gas production leaving the platform to see if the target volumes are reached, or if a well is shut in.
Murphy has implemented this system in all of their operated deepwater assets in the Gulf of Mexico. This paper will give insights on how drastically it transformed the way of doing their daily work, how it changed the way operators work together with engineers, and in addition, an outlook of further improvements to the system based on their experience so far.
Note: All values in the figures at the end of the SPE paper are randomly generated and do not represent reality.
Realizing Single-Diameter Wellbore Technology
Authors: Waddell K. 
Published: December 2007

AbstractThe provenance of the single-diameter well consists of over 350 commercial installations of solid expandable tubular systems and a concise, yet encompassing development plan. The maturation of expandable technology has led to successful design, construction and testing of individual components and the subsequent subsystem that will ultimately help realize the single-diameter well.This evolutionary step brings the energy industry that much closer to a fundamental change in wellbore construction. The single-diameter well represents a paradigm shift in the way wells are drilled and results in significant benefits that include conserving resources, saving time, and creating a smaller environmental footprint. All of these features result in considerable savings that reflect the practicality of this value-added technology.This paper will explain the overall scope, approach and implementation essential to realizing the single-diameter well. In addition, this paper will explain how the technical development of necessary tools for the single-diameter well brings significant savings to drilling operations. Using business cases, this paper will detail where the value of application is realized. In conclusion, this paper will outline future possibilities for the technology and how it will impact the industry.
Enhanced Fitness Program in the Workplace: The Unocal Philippines Inc. Experience
Authors: Surara R. C. , Lacsa R. P. 
Published: December 2007

Abstract

Introduction
To improve employees' interest and participation on the fitness program and maximize utilization of the company's fitness gym equipment, the company's aerobics program was improved to a new fitness program that emphasized cardio- endurance exercise and overall muscle conditioning.

Method
The program was offered to all employees targeting those who were under the cardiovascular/diabetes programs and with weight problems. Lecture on the Benefits of Exercise Nutrition were conducted by the Health & Medical Services. Enrollees were referred to a nutritionist for dietary prescription. A demonstration and return-demonstration of body exercises were facilitated. A two-week daily close monitoring on proper exercise execution was observed to assure efficiency and safety of the training.
Each enrollee has an individual 3-month exercise program developed. The 20-minute aerobics exercise or an equivalent exercise/activity is to be done at least three times per week alternate with weight training exercises for 45 minutes to an hour.
A Fitness Diary was designed and given to each participant as a guide to track their progress after the two-week rigid hands-on training. Participants were advised to visit the clinic on a weekly basis to review their compliance and deficiencies on the program. A baseline measurement of an employee's HRA and weight were taken before the start of the program and after three months.

Results
Thirty-seven employees voluntarily enrolled to the 1st batch of the company's Fitness Program. Out of 37 volunteers, 33 employees completed the program. Compliance - 10 (30.3%) had good compliance to the exercise schedule; 17 (51.5%) with declining compliance or intermittent exercise after two months of good compliance; and 6 (18%) had skipped the weight training portion of the fitness program. HRA results
- 2 employees (6%) have improved their heart risk score; (from moderate to low); 29 (88%) have maintained their risk score; and 2 (6%) had higher scores. Weight - 19 employees (57.5%) have improved from their baselines; 7 (21.2%) have maintained and 7 (21.2%) gained weight.

Conclusion
The enhanced UPI fitness program was well received and more appreciated by the employees, specifically the enrollees. Improved attendance of employees utilizing the fitness gym was noticeably significant. The program is more flexible compared to the previous aerobics program, thus employees were able to perform the prescribed exercises in the company's fitness gym and can also do the exercise program at a local gym or even at their own home. Improvements or reinforcement to sustain participation: strict adherence to the prescribed diet by the participants; an improved monitoring compliance of the parameters; a bigger gym area to accommodate more employees; training for other nurses as gym facilitators; and incentives to enrollees are strongly recommended.
Successful Gas Shutoff With Gel: Evaluation and Implementation, Northeast Venezuela
Authors: Llamedo C. M. A. , Mejias C. F. V. , González C. E. R. , Espinoza R. J. , Valero E. M. , Calis N. 
Published: December 2007

Abstract
Non- Conventional Enhanced Oil Recovery Methods are important for PDVSA in Venezuela in order to increase oil production.
Active improved oil recovery projects in PDVSA oilfields are mainly done by water injection in reservoir flanks, water injection by pattern, and by gas injection in the crest. Most of the production associated to these projects represents more than 40% of the total oil production, which includes condensate, light and medium oil production. In most of the cases, the recovery factor of the water injection projects do not exceeds 30% of original oil in place; whereas in projects under gas injection they can reach a recovery of 45%.
Over the last 7 years, more than 50 wells have been treated with gels formulated at PDVSA-Intevep. The application is considered a successful alternative to improve injection profiles and/or productivity.
In this work the effectiveness of Multigel® for gas shut off is tested. We included the diagnosis, design, and treatment in a producing oil well with a high gas to oil ratio located in North East Venezuela. The design of the treatment with both Multigel® and cement was done to isolate producing gas zones. The selective treatment and the results of the application of the technology are described. In the case of gel treatments a criterion adapted for the calculation of the volume must be used, in order to ensure the success of the application. The selection of a stable polymeric gel system at reservoir conditions is very important to guarantee a secure application and the operational sequence of the treatment. The main conclusion of this work is that there are three essential steps in a successful gel application treatment: diagnosis, design of the treatment and injection of the system in the field. In this application the combined gel-cement technique was used for gas blockade; it showed more effectiveness and assurance the complete seal to gas flow. The well was re-open to production with a low and permissible gas-oil relation, and now it is almost a half of the previous ratio before the treatment.
Formation-Tester-While-Drilling Experience in Caspian Development Projects
Authors: Finneran J. M. , Green C. , Roed H. , Burinda B. J. , Mitchell I. D. C. , Proett M. A. 
Published: December 2007

Abstract
A new formation-tester-while-drilling tool (FTWD) introduced to the Chirag field, in the Caspian Sea, in December 2003 has resulted in significant time savings. As of 1 December 2004, it had been run in two additional wells at Chirag, including the longest well with the greatest step out drilled to date in the Caspian region. Prior its use in this particular well, the tool had been qualified by comparison to wireline measurements which have established its ability to make accurate formation pressure measurements in the high-permeability formations of the field.
Use of the tool has involved improvement and optimization of test procedures to consider better depth control, the possibility of stuck pipe risk, and mud cake integrity. Recent Caspian experience has also included the use of a new 8-in. diameter multi-drawdown version of the tool at the Central Azeri field.
The Chirag field has been producing since 1997 and has been under water flood since 1999. To date, the Pereriv reservoir has produced over 300 million BO from 14 wells. Current oil production is 142 thousand BOPD, and water injection is 135 thousand BWPD.
The reservoir is in a very dynamic state, and FTWD pressure data are critical to reservoir management. Specifically, layer pressure data is used to tune the reservoir simulator, monitor injection response, and map dynamic fluid gradients in the field.
This paper focuses on experience from the use of GeoTap tool compared to wireline tester results at the subject fields including highlights of operational learning points.
Survival Analysis: The Statistically Rigorous Method for Analyzing Electrical Submersible Pump System Performance
Authors: Bailey W. J. , Weir I. S. , Couët B. , Hogan J. 
Published: December 2007

Abstract
A rigorous statistical methodology using survival analysis was developed and applied to electrical submersible pump (ESP) system performance data. The approach extracts unbiased information from performance data and permits lifetime modelling using parameter combinations employing all available data. The analysis explicitly accounts for ESPs that are still operational at the time of the study, thus removing a historical source of statistical bias. The analysis uses Kaplan-Meier and Cox proportional hazards modelling to determine statistical significance of explanatory variables. Methods developed to facilitate explanatory variable factor collapsing are also discussed (the partitioning of levels of each factor into nonempty subsets of statistically similar response) so that an acceptable degree of parsimony is achieved. Essential definitions necessary for preliminary data structure are also covered.
We demonstrate the practical utility of this methodology on a comprehensive data set to enable unbiased and conclusive appraisal of ESP performance, thereby resolving a common concern about comparative system reckoning. The paper concludes that survival analysis, suitably applied to properly censored data, is essentially the only reliable method of evaluating ESP system performance (and other types of time-to-event data).
Limiting Scale Risk at Production Wells by Management of PWRI Wells
Authors: Mackay Eric J. 
Published: December 2007

Abstract
Mixing of injected seawater with formation brines may cause scale precipitation at production wells and surface facilities, but does not generally cause significant damage within the formation itself. Indeed, mixing within the reservoir may be beneficial, if the concentration of scaling ions is reduced due to ion stripping as the brine mixture approaches the production well1. One potential exception to this is when the availability of produced water for re-injection (PWRI) is insufficient to maintain voidage replacement, and must be supplemented with seawater. Under such circumstances, seawater and formation brine may be completely mixed before injection. This will not lead to a loss of injectivity if scale inhibitor chemicals are appropriately applied to the injected brine stream2.
However, scale inhibitors are retained by the reservoir rock as they are displaced away from the wellbore, resulting in the inhibitor front propagating more slowly than the saturation front - usually referred to as chemical retardation. As brine is displaced away from the injection well, the upshot is a growing zone of mixed brine with chemical concentration below the threshold required to inhibit the scaling reaction.
The question this paper considers that has not been addressed before is whether the ratio of produced water to seawater that is injected, the possibility of treating the injection brine mix with inhibitor, and field specific details such as the location of the injection wells relative to production wells and the aquifer can impact how this zone of unprotected mixed brine is displaced and reacts deep within the reservoir, away from both injection and production wells. If the scaling reaction can be limited to a region deep within the reservoir where the volume of rock is large compared with the potential mass of scale that may deposit, then the sulphate ions associated with seawater may be stripped from the brine mixture before the water is produced. Thus, by considered yet straightforward management of the PWRI scheme, it may be possible to protect the production wells from scale damage in a way that is not possible under conventional seawater injection. This hypothesis is tested using conventional reservoir simulators and reaction-transport modelling. Various conditions are considered, including brine reactions, extent of brine displacement through the oil leg or aquifer, as well as management of the PWRI wells. Prediction of scale damage potential at production wells is made for an example field system.
Valhall Field: Microfracture Acquisition Using Wireline-Formation-Tester Tools To Validate Fracture Confinement
Authors: Olson K. E. , O'Keefe M. , Nicholyasen A. , Cameron D. 
Published: December 2007

AbstractProppant fractures have been performed in the Valhall Field since 1986 with over 200 proppant fractures completed to date. Prior to the development of the flank regions of the Valhall field in April of 2003 the majority of the proppant fractures were executed in the crest of the field and were confined to the producing interval due to considerable pressure depletion. It was identified that 50% of the new wells in the flank would be completed in near original reservoir pressure regimes. A critical component to designing and optimizing the proppant fractures for the high pressure flank wells was to have a good understanding of fracture confinement. A stress profile between the overburden and producing interval was generated using leak off test (LOT) in the overburden and closure pressures from previous fracture stimulations. Interpretation of the data was unclear due to the scatter in the LOT. Front end work to optimize the proppant fracture spacing and size along the horizontal laterals clearly showed the need for better closure pressure data, especially in the overburden.A wireline formation test (WFT) MicroFrac operation performed on a Valhall Flank well in January 2004 confirmed that proppant fractures in flank wells with close to original pore pressure would grow unconfined into the overburden. This confirmation caused a revision in the Valhall stimulation strategy for high pore pressure wells. It also yielded savings of potentially more than $500,000 per well by further optimizing the number of proppant fractures and stimulation size.The MicroFrac's were performed in both the overburden and producing zones in combination with planned WFT operations to obtain formation pressures, water samples and determine movable water if an oil water contact (OWC) was encountered. The operations were monitored real time in the BP Onshore Operations Center with feedback provided to the logging engineer offshore via video link. Due to rig time constraints all planned WFT data acquisition objectives were to be realized in a single run. The value of the WFT operation was maximized when planned and executed by a multi-disciplinary team with real time operational input from the end user of the data.