bluuebunny/crossref_metadata_2025 huggingface dataset:
Drilling Offshore HT/HP Wells in Environmentally Sensitive Area Using Water-Based Mud
Authors: Desai Harshit , Affes Sami , Rahman Mizan , Williams Gregg
Published: December 2007

Drilling an exploratory well in the lower cretaceous formation of the Krishna Godavari (KG) Basin on the East coast of India poses a host of technical, logistical and environmental challenges. The technical demands were particularly acute when designing a drilling fluid to address the ultra-HTHP environment, the lack of offset data making it difficult to predict pore pressure, low seismic resolution and the highly environmentally sensitive ecosystem. While the technical demands downhole made oil-base (OBM) drilling fluids the system of choice from an operational perspective, the location of the block near a wildlife sanctuary, posed a host of logistical problems, in addition to the exorbitant costs associated with modifying the rig to comply with zero discharge restrictions required when using invert-emulsion drilling fluids. Thus, the operator embarked on a fast-track campaign to design a water-base (WBM) drilling fluid system that would not only meet the technical demands, but also address the environmental limitations.

This paper describes the design, execution and evaluation of the water-base drilling fluids employed on two HTHP wells in the KG Basin. This authors will discuss the effective use of a specially engineered KCl/Glycol system to drill 2000m of clay stone section in the 12¼ hole and the use of a low-colloid and contaminant-resistant water-base drilling fluid to reduce HTHP fluid loss values, improve shale inhibition, increase lubricity and reduce differential sticking potential for the formation. The first HTHP well in the block was drilled to 5061m with BHP of 11,800 psi and BHST of 410°F and presented a host of well problems due to the severe drilling environment. The nature of the formation coupled with the use of WBM limited the ability to achieve the logging objectives of the discovery well.

The high performance required of the WBM was compounded dramatically when planning the second HTHP well, which was to be drilled deviated to 5710m. Based on the results of the second HTHP well, the low-colloidal HTHT water-base mud system has proved to be an ideal alternative solution to the OBM. In addition, the authors will discuss the successful application of a mechanical earth model in predicting the pore pressure and helping WBM in achieving the target of drilling the deepest and most extreme environment well ever in India.
Estimation of Average Reservoir Pressure and Drainage Area in Naturally Fractured Reservoirs—Tiab's Direct Synthesis
Authors: Igbokoyi A. O. , Tiab D.
Published: December 2007

Average reservoir pressure in a naturally fractured reservoir is usually computed in a similar way with that of a conventional homogeneous reservoir. However, because of the different flow regimes that exist in the pressure transient test of a naturally fractured reservoir, it is necessary to understand the implication of each flow regime on the estimation of average reservoir pressure. This work presents solution methodology for pseudo-steady state behavior of a naturally fractured reservoir under commonly identified flow regimes coupled with matrix flow behavior.

The matrix flow behaviors investigated are pseudo-steady state and transient flow in the matrix blocks. Different matrix block flow models are used to analyze the reservoir pseudo-steady state behavior. A new approach to pseudo-steady state sugar cube model is also presented and the result obtained using the new approach is compared with the Warren and Root model. Finally, Tiab's Direct Synthesis (TDS) technique is applied in the computation of the average reservoir pressure.
Drilling and Petroleum Engineering Program and Project Management at Santos Ltd.
Authors: Horton G. , Dedigama T.
Published: December 2007

PRISM (Plan Resource Implement Schedule Manage) is a project management toolkit developed to facilitate the field operations of the Petroleum Engineering department of Santos Ltd. for onshore Australia. It is believed that PRISM is unique in its functions when compared to other off-the-shelf project management applications. Currently PRISM enables the management of approximately 1200 projects (including in excess of 250 drill, complete and connect projects) being implemented by five major and four minor field resource types, comprising up to 20 major and 40 minor individual field resource packages that are deployed daily. These represent approximately A$450 million of activity planned for implementation in 2006.

PRISM allows real time reporting and updates to resource schedules during project implementation. It is used for near term schedule management, longer term forecasting and reporting, enabling the field resource schedules to be optimised as project scopes evolve. Unique interfaces have been developed to allow the inherent volatility of petroleum engineering operations to be managed and communicated to office and field based personnel on a daily basis.

The development of the PRISM application integrated and replaced a number of individual scheduling tools and reporting systems. It has allowed all stakeholders to better understand project requirements and status of implementation. The result has been better utilised field resources running more continuously, in conjunction with increasing work activity and complexity of downhole completions and the introduction of new technology. Scheduling performance has improved despite the increased number of projects, their scope and complexity.

A major part of the PRISM rollout process has been to gain user acceptance and encourage users to use the toolkit, both as a source of information on projects and to keep details updated. This paper also looks at the project implementation and rollout process, including barriers and lessons learned.
Superior Zonal Isolation Provided by Ultralightweight Cementing Technology Increases Profitability of Wells in Difficult-to-Cement Areas
Authors: Kulakofsky D. , Avalos A. , Hernandez R.
Published: December 2007

Today operators are forced to drill in increasingly challenging environments in an effort to meet a growing global demand for petroleum products. In Mexico, meeting this challenge requires more skills and innovative materials from oilwell cementing providers. Nowhere else in the world are the cementing requirements more difficult than those presented by Cantarell and other depleted zones and weaker formations present in Mexico. New ultra-light foamed cementing technology enables successful circulation and an effective seal, which can have a great impact on not only the cost of drilling a well, but on the productive life of the well. In addition to the easily quantified benefits from reduced water production, reduced remedial costs, decreased drilling days and increased hydrocarbon production, additional profitability stems from the more difficult to quantify areas such as delays in production delivery and early water production.

Traditionally, the lower limit for oilwell cementing has been 7.5 to 8.5 lb/gal. When the density of the cement slurry was reduced down to these light weights, it was still not low enough and the industry had to live with losses or attempt multi-stage cement jobs. In Cantarell, where a 7.3-lb/gal cement job was once attempted, these slurries were not light enough. Recent developments in ultra-light foam technologies have allowed the successful application of production quality foam cements delivered at downhole densities as low as 5 lb/gal.

This paper presents case histories from Mexican wells, which show how this ultra-lightweight foamed cement slurry technology was used to decrease costs and increase production, yielding more profitable wells for the operator.
Case Studies for Improving Completion Design Through Comprehensive Well-Performance Modeling
Authors: Ouyang Liang-Biao , Huang W. S.
Published: December 2007

Optimal completion design has been practiced over the past years through detailed well performance evaluation, and improved completion selection workflow. Six field case studies will be discussed in this paper to demonstrate the methodology to achieve the best completion design under different field and operating conditions. The focus of the field case studies covers well production prediction, well performance evaluation, optimum well length assessment, cost effective and production efficient completion strategy, skin estimate from well production history, water/gas control, impact of casing integrity, and sensitivity assessment on reservoir permeability, mechanical skin, non-Darcy skin, flowing bottomhole pressure (BHP), original oil saturation, and so on. The wells to be discussed include single, dual lateral horizontal wells, and highly deviated wells. The produced fluids include oil and/or gas and water. The most popular completion options, such as open hole, slotted liner, inflow control devices (ICD), intelligent well completions (DIACS), perforated cemented liner, wire wrapped screen or standalone screen, gravel pack, and frac pack, expandable sand screen, alternating standalone screen and blank pipe, etc, have been either applied and/or evaluated in the case studies.
Futures-Based Modeling of the Oil Price for Realistic E&P-Project Valuation
Authors: Staber Stephan
Published: December 2007

The net present value of an E&P-project is still the most important investment criteria in oil field acquisitions. Besides the discount rate assumption and the estimation of the strategic value of an E&P-project, the oil price assumption is the most important input parameter in E&P-project calculations. Even small variations in the oil price assumption can have large influence on the resulting project value. Therefore, for a realistic E&P-project valuation it is critical to use sophisticated methods for the estimation of the future oil price.

In the past, it was common practice to simply assume a fixed value for the long-term oil price (flat price); others use forward curves as a forecast (floating price). In probabilistic calculations (e.g. in Monte Carlo simulation) and in using the option pricing theory for valuing real options, stochastic processes are modeled. Here, the oil price is predominantly considered as to follow a Geometric Brownian Motion or a type of a Mean Reverting Process.

This paper presents an improved concept for modeling short- and long-term oil prices. The method is based on the premise that forward and future prices are the markets best guess of future oil prices. The future or forward curve is utilized as the expected value curve for the Mean Reverting Process. Thus, the oil price is modeled in a way that makes the resulting oil price assumption suitable for incorporating it in traditional net present value calculation as well as in sophisticated real option valuations. On the one hand for the discounted cash flow method it is critical to use reasonable short- and long-term values for the oil price, on the other hand for real options valuation it is necessary to model the oil price stochastically. The presented improved method fulfils both basic requirements and is therefore a strong improvement to common E&P-project valuations.
Dual Purpose Reversible Reservoir Drill-In Fluid Provides the Perfect Solution for Drilling and Completion Efficiency of a Reservoir
Authors: Ali Syed , Luyster Mark , Patel Arvind
Published: December 2007

Ideally, a reservoir drill-in fluid (RDF) possessing both an oil external phase for drilling and a water external phase for completion would provide the ideal solution for drilling and completing a well. Through the manipulation of surfactant chemistry, a novel reversible invert emulsion drilling system, which provides both attributes, has been developed. During drilling, an operator can utilize the reversible oil-based mud to take advantage of the commonly accepted properties that enhance the drilling efficiency and then convert this system to a water-based fluid to improve the completion efficiency.

The amine-based surfactants used in the reversible invert system are strong emulsifiers in an alkaline medium; however these same emulsifiers become more common direct oil-in-water emulsifiers in the presence of protonating agents such as acid. This process of protonation and deprotonation of emulsifiers controls the emulsion phase of this drilling system and thereby, the oil-wetting and water-wetting characteristics of the subsequent filtercake and entrained solids. As the bridging agents in filtercake are commonly calcium carbonate, once water-wet (in presence of acid) promote clean-up and thus, are readily consumed by common acids that may be utilized during the completion phase.

This system was field trialed with success for drilling and completing an injector in the first quarter of 2000. Since this initial application, numerous completions have utilized this reversible invert RDF system. This system has been successfully applied to a variety of completions, in particular: injectors and producers, openhole gravel-packs (OHGP), expandables and standalone as well as various environments and reservoirs. Theoretically, this system also provides advantages with respect to common cementing and environmental issues.

This paper presents the development of this multi-purpose drilling and completion system and discusses the application of this technology to adapt to the challenges of evolving global completion complexity.

Several case history examples are presented from selected completions. The paper includes the laboratory pre-planning and field data illustrating the concerns and the development of a solution with respect to drilling and clean-up.
Developing Heavy-Oil Field by Well Placement-A Case Study
Authors: li Pan You , Hong Luo Hui , Sharara Abdel Mageed , Naganathan Sivaraman
Published: December 2007

Fula is a heavy oil field located in Muglad basin in Sudan. Aradéiba reservoir in the field consists of highly heterogeneous sandstone that is thinly bedded, unconsolidated, bearing typical heavy oil. Bentiu reservoir is composed of massive sandstone, unconsolidated and traped very high viscous oil. Production performance of vertical wells indicates that the reservoirs are facing problems of low productivity, bottom water conning and sand production. In his circumstance CNPCIS set itself a daunting task of tripling the production in less than a year.

Horizontal wells were considered as best option for improving the productivity in this small to medium sized heavy oil field, and controlling the sand production due to low drawdown pressure and increased exposure the reservoir.

This paper discusses about comprehensive geological study, identification of target oil pools, well design, selection of fit for purpose technologies and the complete well placement cycle including detailed analysis on the drilling and steering challenges while placing horizontal well through reactive shales and channel sand environmentThe paper also discusses about various completion strategies, the results of well placement, value of using new technology, lessons learnt and cost/production analysis.

Team work, communication, knowledge sharing and deployment of fit for purpose technologies has resulted in a five fold increase in production through horizontal wells compared to vertical wells with no sand production. The paper illustrates how integration of different disciplines led to successful well placement, enhanced production with sand and water management in heavy oil environment.
Auto, Natural or In-Situ Gas Lift Systems Explained
Authors: Vasper Adam
Published: December 2007

The terms auto, natural or in-situ gas-lift all refer to artificial lift systems that use gas from a gas bearing formation to gas-lift a well. The gas-lift gas is produced downhole and bled into the production tubing via an auto gas-lift valve designed for gas operations.

The value of auto gas-lift is probably easier to demonstrate than for other types of intelligent well because it provides a direct replacement for conventional gas-lift equipment, compressors, pipelines and the ancillary equipment they require.

An estimated 60 auto gas-lift systems have been installed at the time of writing this paper, most of them in the Scandinavian sector of the North Sea. Several papers have discussed this technology but, so far, none have presented a rigorous analysis or solution of the wells’ production from a gas-lift perspective.

This paper presents the basic theory behind auto gas-lift and how to apply it. The components of the theory are well known and commonly used in Nodal analysis and conventional gas-lift design. Properly combining these components allows an auto gas-lifted well's performance to be calculated and downhole equipment to be correctly sized and located.
A New Class of ‘Green’ Corrosion Inhibitors, Development and Application
Authors: Craddock H. A. , Caird S. , Wilkinson H. , Guzmann M.
Published: December 2007

The chemical application of corrosion inhibitors is a widely adopted practice in production and processing operations in the Oil and Gas Industry. Particularly challenging is the development of new chemistries, which maintain good protection of materials under a variety of conditions whilst being environmentally acceptable.

This paper illustrates patented work (jointly patented by BASF and Roemex Ltd, Patent Numbers AE 20051110/Wei PF0000057382/Wei) in the chemistry of Alkylpolyglucosides (APGs) and their synergistic effect with polyaspartates.

This paper outlines the development of this inhibitor class, which demonstrates good general inhibitor performance in a number of oilfield brines, shows good filming characteristics under conditions of shear and also has an excellent environmental profile.

The paper will examine the base chemistry of the alkylpolyglucosides.

The paper will illustrate a number of sweet and sour conditions as well as various temperature conditions, in a variety of oilfield waters. The results of laboratory tests under these conditions such as linear polarisation resistivity (LPR) the so-called "bubble test" and Rotating Cylinder Electrode (RCE) will be displayed and presented. The paper will further illustrate the preferential partitioning behaviour of these chemistries to the aqueous phase and their non-emulsifying tendency.

Environmental data on formulated products will also be given. To date all formulations of this chemistry have been classified for use in the UK sector as Gold with no substitution and other product warnings.
Compact Multiphase Inline Water Separation (IWS) System—A New Approach for Produced Water Management and Production Enhancement
Authors: Wang Shoubo , Gomez Luis , Mohan Ram , Shoham Ovadia , Fang Zaixin , Xiao Jinjiang , Al-Muraikhi Ahmad , Al-Dawas Saleh
Published: December 2007

A fully instrumented compact multiphase Inline Water Separation (IWS) system1 has been developed to separate a significant portion of the produced water from a production stream, with the remaining production fluids (gas, oil and the rest reduced amount of the water) sent to existing processing facilities. The quality of the separated water meets the requirement for water injection or direct disposal. The system consists of a Gas-Liquid Cylindrical Cyclone (GLCC©2), a Liquid-Liquid Pipe Separator (LLPS), a Liquid-Liquid Cylindrical Cyclone (LLCC©3) and a two-stage Liquid-Liquid Hydrocyclones (LLHC). The compact IWS can be installed either at the wellhead or downstream of a production manifold to handle multiple wells on land, offshore platform or sea floor. The benefit of such a system includes increasing field water handling capacity, reducing the size and cost of the downstream separation facility, and reviving dead low-pressure wells.

A prototype compact IWS system has been tested under field conditions. Initially the individual compact separator units have been tested separately and optimized for maximum separation efficiency. The results of the IWS system tests show that it is feasible to integrate GLCC, LLCC, LLPS and LLHC into a compact multiphase separation system for bulk produced water removal from a production stream. The overall water separation efficiency, defined as the percentage of water removed from the total water production, up to 80%. The outlet water quality is less than 200 ppm oil concentration, which meets the expection of this study. A second stage LLHC can be used for further polishing the water quality to meet the requirement of water injection or direct disposal. The control systems for GLCC liquid level control and LLHC differential pressure ratio control were also tested under slug flow conditions.
Review of the State-of-the-Art Gas/Liquid Cylindrical Cyclone (GLCC) Technology— Field Applications
Authors: Kouba Gene , Wang Shoubo , Gomez Luis , Mohan Ram , Shoham Ovadia
Published: December 2007

The Gas-Liquid Cylindrical Cyclone (GLCC) has repeatedly proven itself in laboratory and field tests, as well as in actual field applications, as a viable alternative to the conventional gravity-based gas/liquid separator. Large conventional gravity-based vessels have been relied upon since the inception of the petroleum industry to separate oilfield production of oil, water, sand, and gas. However, economic and operational pressures continue to force the petroleum industry to seek smaller, less expensive and more appropriate separation alternatives in the form of compact separators, especially for offshore and subsea applications. As compared to the vessel-type separators, a compact separator such as the GLCC is a simple, low-cost, low-weight separator that requires little maintenance and is easy to install and operate. Furthermore, the capabilities to accurately predict various performance characteristics, e.g., liquid carry-over and gas carry-under, of the GLCC have far surpassed those capabilities for conventional vessel type separators. The scope of this paper is to present the state-of-the-art of the GLCC technology for variety of applications in the oil and gas industry.

At present, over 1,000 GLCCs have been installed in fields around the world. Details of typical field applications are presented and discussed in this paper. In addition, data from field type facilities, namely, Texaco's Humble flow loop and Colorado Engineering Experiment Station Inc. (CEESI) are presented. These data illustrate GLCC performance at high pressures (up to 1,000 psi) with a variety of hydrocarbon fluids. The results presented include, gas carry-under (GCU), liquid carry-over (LCO) and GLCC control data. Additional field testing of the first integrated GLCC compact separation system carried out in Daqing oil field experiment station are also presented.

The technology for state-of-the-art GLCC field applications and some laboratory and field testing results presented in this study, will help petroleum engineers to better understand, design and deploy GLCC technology in their field operations.
Microbe-Enhanced Oil Recovery Technology Obtains Huge Success in Low-Permeability Reservoirs in Daqing Oilfield
Authors: Wankui Guo , Chengfang Shi , Zhenyu Yang , Zhaowei Hou , Rui Jin , Ying Wang , Jiyuan Zhang , Guanghao Shan
Published: December 2007

Based on the MEOR mechanism study of Brevibacillus brevis and Bacillus cereus, From 2002 to 2004, the two strain and other microbes were applied in the microbial huff and puff as well as the Microbial enhanced waterflood test in Daqing excessively low permeability (1.0md-25md) reservoir. After bacteria injection, 44 among the 60 huff and puff wells shows a significant oil production response—the accumulative oil increment reaches 9175.5 tons and the input-output ratio amounts to 1: 8. The Microbial enhanced waterflood test carried out in June 2004 also provides a satisfying result. After the injection of bacteria, the pressure in the two water injectors decreased more than 2MPa, which results in an injection capacity increase. The Analyse result of production fluid indicate that the selected bacteria can adapt the stratum conditions better and can grow and reproduce. They degrade heavy hydrocarbon, improve character of crude oil and metabolize active substances. The fluid production of trial field increase and water cut decline. in late 2005, 7 production wells among 10 production wells get good effect. Fluid production increased from 50.7 tons per day (before bacteria injection) to 68.3 tons per day, and the corresponding water cut declined from 46.8% to 40.3%.oil production is increased from 24.7 tons per day (before bacteria injection) to 40.8 tons per day. The accumulative oil increment more than 5800tons and the input/output ratio is 1:5. These make MEOR a very promising and effective oil recovery method in Daqing low permeabilityreservoirs.
Case Study: Optimizing Hydraulic Fracturing Performance in Northeastern United States Fractured Shale Formations
Authors: Paktinat J. , Pinkhouse J. A. , Johnson N. , Williams C. , Lash G. G. , Penny G. S. , Goff D. A.
Published: December 2007

The primary purpose of stimulating fractured shale formations is to extend the drainage radius by creating a long fracture sand pack that connects natural fractures and increases flow channels to the wellbore. However, most of the fracturing pad fluid leaks off into natural fractures resulting in shorter effective fracture lengths and a significant damage zone surrounding the fracture. This is due in part to inadequate fluid loss control properties of the injected fluid and high capillary forces that retain fluid in the formation. Surfactants are used to lower high capillary forces and help well cleanup of the injected fluids. However, many of these additives adsorb rapidly within the first few inches of the shale formation, reducing their effectiveness and resulting in phase trapping of the injected fluid.

In this work, laboratory data is presented for various fracturing fluids with different surface activity pumped into the Rhinestreet Shale. Recent fracture treatments have been successful utilizing a slick water treatment consisting of water and dry polyacrylamide polymer with and without surfactants. Commonly used surfactants as well as a microemulsion system are evaluated in this study.

Laboratory data is presented illustrating how a microemulsion accelerates post fracturing fluid cleanup in tight shale cores. Addition of microemulsion to the fracturing fluid also results in lowering pressure to displace injected fluids from low permeability core samples and proppant packs. When microemulsion is incorporated at 2 gpt within the fracturing fluid; the relative permeability to gas is increased substantially while water saturation is decreased. This alteration of the fracturing fluid effectively lowers the capillary pressure and capillary end effect associated with fractures in low permeability reservoirs by as much as 50%, thus mitigating phase trapping and therefore permitting an increased flow area to the fracture, hence longer effective fracture lengths.
Methodology of Optimal Well Pattern, Location and Paths in Productive Formations During Oil and Gas Fields Development Planning
Authors: Larionov A. , Nifantov A. , Itkin V. , Alexandrov V.
Published: December 2007

The wells location issue in a productive formation is an important aspect of the effective field development. The problem solution is impossible on the intuitive level due to the reservoir inhomogeneity.

At present the well path is accepted to be located basing on the famous criteria, specialist experience and hydrodynamical simulation on a reservoir model. The designer should analyze many field development variants with different well spacing during limited time interval.

The self-doped tool is invented for decision-making support at the fields development planning. It reduces the time of the field development scenarios making and analyzing. To solve the multimodal optimization problem the 1D discrete optimization methods, the genetic and Ant Colony algorithms are applied.

The methodology-distinguishing feature is an additional capability to design well paths prescribed by spatial curves. The maximum crookedness drilling limitations are kept.

The numerical simulation software is built for the field development efficiency determining. The optimum is calculated on the maximization results of cumulative production, gas production ratio or net profit.

On practice, the project production rate is not guaranteed by the optimal well location defined on simulation. Depending on the making of borehole into the planned reservoir zone, the well drilling quality defines the production indices. To solve the problem the contemporary well drilling supervisor methods are used. They include the method and information support. The information system of technology control allows reconstructing the consistency of operations and staff actions at the well site. As a result, the well planning and conduction experience collected at the formalized database is used during next well planning.

In the study, the approach of combining the field development automated planning, well pattern calculating and borehole drill control is applied. Using the modern Internet-technology advantages, it introduces the convenient features for real-time joint work of designers and supervisors.
Cements and Gas Well Cementing in the Arctic Regions of Russia
Authors: Klyusov Anatoly A. , Rybokon Alexandr A. , Frolov Andrey A. , Klyusov Vsevolod A.
Published: December 2007

The paper presents geocryological characteristics of the main gas and gas condensate fields, standard well design, typical problems occurring during well construction and methods of well cementing in permafrost and soft rocks. Hydration process and Portland cement hardening at a low temperature are considered along with erroneous concepts of the formation of cement stone in annular space of low temperature wells, taking into account the influence of temperature gradient and negative effect of "thermal" method of hardening stimulation. Basic requirements for oil-well cements are formulated and the method of their testing in arctic conditions is refined. The information about cements and additives for arctic wells, their meeting the API standard and the reasons and methods of gas flow prevention in permafrost is given.
Education in Petroleum Engineering Delivered by Tomsk Polytechnic University (Tomsk, Russia) And Heriot-Watt University (Edinburgh, UK)
Authors: Pokholkov Yu. P. , Koshovkin I. N. , Dmitriev A. Yu. , Kulagina T. E. , Parnachov S. V. , Ford J.
Published: December 2007

The idea of creating a Centre that would train world-class experts in petroleum engineering in Russia was first voiced in September 2000. Being one of the leaders of Russian technical education, Tomsk Polytechnic University became the basis for the Centre.
Numerical Method of Evaluating Elemental Content of Oil-Water Saturated Formations Based on Pulsed Neutron-Gamma Inelastic Log Data
Authors: Khisamutdinov A. I. , Phedorin M. A.
Published: December 2007

A new numerical method is proposed for solving an inverse problem of pulsed neutron-gamma inelastic log . The matter is to determine a composition of fluid and rock skeleton by gamma-ray measurement data in spectral windows of four elements: C, O, Ca, Si. Inverse of the data is based on iteration procedure, on each step of that the corresponding direct problem is solved for transport equations of neutrons and gamma quanta. Results of numerical experiments are presented which confirm a convergence to exact solution for the most of unknowns. The proposed numerical method is development of general approach for solving inverse problem in nuclear geophysics early considered [1-5].
Reservoir Modeling—Automatic Well Log Data Correlation Using "AutoCorr" Software
Authors: Gutman Igor , Balaban Ivan , Kuznetsova Galina , Staroverov Vladimir
Published: December 2007

Well correlation is the key process while creating geological model of oil reservoirs for the fields having dense wells network and hence the process determines effectively all following steps of oil production.

The well correlation consists of mapping one well's intervals to another wells. It is a special case of one of the most complicated mathematical problem so called image recognition problem. The basic difficulty of automatic correlation of well intervals is the fact that in advance it is not known which stratigraphic horizons were kept unchanged in both wells and which are washed away or subject to other distortions.

This technical report shows opportunities of automatic well correlation procedure, as they developed in a software package "AutoCorr" and how these opportunities are used in oil deposits modeling. Continuous process of automatic modeling of oil reservoirs as it is carried out in a package is considered: loading initial data, detailed well correlation, loading geophysical interpretation results, fluids and gas contacts level determination, construction of geological profiles, maps, reserves evaluation and transition to three-dimensional geological modeling. The attention is given to a number of the important questions solved at automatic correlation: construction of wells plan triangulation, well pair correlation, correlation error estimation, transition from well pair's correlation to construction of the whole deposit detailed correlation scheme tracking high porosity intervals as ways of a fluids filtration, a parity of automatic and interactive methods of correlation.

It is noted in the paper that use of the offered automatic correlation changes, in comparison with traditional approaches, some essential aspects of work. The first is that requirements to quality of initial data increase. The second is that the volume of routine manual work during correlation is reduced because the basic attention is given the correlation in some complex areas and the significant part of work is carried out automatically. The third is that the volume of creative making work increases. Automatic well correlation gives opportunities for in-depth study of geological object, fast checking of various hypotheses layers behavior, inclusion in a structural skeleton of model of many additional details. The main positive results are better correlation result, greater productivity and more exact and detailed geological model.
Technical Competence Assessment System for Oil & Gas Company Personnel; Increasing Training Efficiency Through Short Courses
Authors: Dmitriev A. U. , Brusnitsyn D. N.
Published: December 2007

It is obvious that the successful development of an oil & gas company largely depends on a consistent system of personnel training and development. To optimize such a system, there has to be a method ensuring maximum training efficiency.

This method that takes into account most advanced Russian and Western technologies was developed by Heriot-Watt Approved Support Centre at TPU. This System of Assessing Technical Competence of Oil & Gas Personnel is now successfully implemented at OAO "Sibneft-Noyabrskneftegaz". Assessing tools, including the software, are used by the Company HR managers to assess technical competence of the personnel without any outside assistance. Recommendations for personnel development are further taken into account when planning Company's technical training programs for the employees. Skill assessment is an established procedure used for identifying personnel needs for technical training. Individual development plans for the employees are developed for the same purposes, the next step being the development of integrated corporate training programs. When a certain stage is completed, another assessment is performed in order to monitor employee's progress or adjust the plans.

This article covers various issues of applying skill assessment techniques based on the experience with OAO "Sibneft-Noyabrskneftegaz" (Noyabrsk, Russia).
Modeling of Petroleum Migration for the Part of West Siberian Basin
Authors: Baranov V. E.
Published: December 2007

During the work a 3D model of oil migration for Jurassic petroleum system in the area of interest was created. Modelling was based on the MPath software developed by the Permedia Group, Ottawa, Canada.

An integrated approach to the evaluation was taken including analysis of geochemical dataset, and geological information. 3-D cube with grid resolution 500x500 m was constructed from the map horizons built on the base of interpretation of 2-D seismic realized within the studied territory during resent 20 years.

In order to provide complex analysis of petroleum system a number of its elements were evaluated: distribution and quality of source rock, including its richness and maturation of source rock; thermal history of the basin; quality and distribution of reservoir rocks including analysis of capillary threshold pressures; paleostructural setting of the territory during migration history.

According to the geochemical source rock and oil correlation, Bazhenov formation was considered as a principle source rock for the studied area.

Expulsion modelling demonstrates that main kitchen areas are confined to depressions located in the eastern and north-eastern part of the territory – Yuzhno-Koltogor depression and Ilyahskiy Flexure. The main migration scenario suggests that that oil migrated stratigraphically downwards from Bazhenov source rock, then lateral migration in fill-spill manner occurred in the Upper Vasyugan J1 carrier beds.

Model obtained shows good predictive power in reconstruction of secondary migration processes and demonstrates rather good correlation with real data. Moreover, model obtained allows proposing increase in STOOIP for several low studied "small" fields located within the area.
Geochemical Aspects of Oil-Gas-Bearing Capacity of Precambrian Deposits of Ancient Russian Platforms
Authors: Bazhenova O. K. , Bazhenova T. K. , Fadeeva N. P.
Published: December 2007

Geochemical investigations are being an inalienable part of oil-geological researches and are being hold at different stages. Regional investigation stage is not finished during the stage investigations of Precambrian deposits of ancient platforms. The main task of geochemical investigations during this stage includes emphasizing of oil-source horizons, their qualitative and quantitative characteristics: determination of genetic types of organic matter, its maturity level, oil-source potential and its realization degree, investigation of composition of naphtides (in case they exist) and possible determination of genetic connections of them with concrete oil-source horizons.

Perspectives of oil-bearing capacity of the regions from the geochemical point of view are being determined by the productivity of oil- and gas-formation centers, i.e. presence of oil- and gas-source rocks of sufficient thickness and organic matter maturity level.
Development Technique and Practice of Horizontal Wells for Complex Fault-Block Reservoirs in Jidong Oil Field
Authors: Hai-min Zhou , Chang Xue-jun , Hao Jian-ming , Jia-peng Zheng
Published: December 2007

Jidong is a typical small-complex fault-block reservoir in fault basin of Bohai Bay. On the basis of the fine description of the reservoir, the new developed horizontal well technique is generalized and applied. The applied scale of the horizontal well technique to the development of Jidong complex fault-block reservoir is speedily extended and the fine result is achieved in lastly two years. In the application of the horizontal well development technique, such series of the horizontal well development techniques as adaptability evaluation of the horizontal wells, scheme deployment, design, drilling, well logging, borehole log, oil production and production management suitable for the features of the complex fault-block reservoir are gradually formed with keeping search and summary. The matching utilization of the technique effectively ensures the applied result of the horizontal well development technique of the small-complex fault-block reservoirs in Jidong Oilfield and it establishes the good fundament for further promoting the advancement of the horizontal well technique. The reservoir with multi-reservoir, small fault-block, bedded edge-bottom waterflood in Gao 63 fault block of the south area in the shallow formation in Gaoshangpu Oilfield, high-effective development for the difficult-to-production reserves in Ng8 subzone of the reservoir for the north area in the shallow formation in Gaoshangpu Oilfield and the practice of high-effective potential by the slim-hole sidetracking horizontal well for improving the development efficiency in the maturing oilfields prove the validity of the method.
Viscosity Conversion of Viscometer Viscosity to Macroscopic Flow Viscosity of Non-Newtonian Fluid
Authors: Liu Mingxin , Shen Pingping , Shi Bingbo , Guo Tongcui , Zhu Bing
Published: December 2007

In porous media, fluid flows through mesh structure made up of micro-braided capillary. Its flow state is similar to the flow in capillary. For Non-Newtonian fluid, we considered viscosity changes with shear strain rate (transformed to pressure difference) in reservoir simulator. It directly uses rhelogical relationship measured by viscometers, but it doesn't consider flow factor in micro-pore. Therefore for Non-Newtonian fluid we educed viscosity transfer relationship between macro- viscosity (viscometer rhelogical formula) and apparent viscosity (flow in capillary), it can be used in reservoir simulator, and it can reflect the difference between micro-flow and the normal flow.
Application of EOR Technology by Means of Polymer Flooding in Bohai Oil Fields
Authors: Han Ming , Xiang Wentao , Zhang Jian , Jiang Wei , Sun Fujie
Published: December 2007

Enhanced oil recovery by means of polymer flooding is considered as an important technology for the strategic development of offshore oilfields in China. The implementation of polymer flooding in the offshore oilfields requires overcoming several major technical problems caused largely by the absence of a fresh water source and limited space on the platform. A pilot test of polymer flooding was conducted in SZ36-1 Oilfield located in Bohai Bay, China. The problems mentioned above were solved through the development of (1) a hydrophobically associating polymer tolerant to salts in the brine and produced water and (2) a portable automatic injection unit. The significant incremental oil and decrement of water cut were observed after 8 months of polymer injection. The successful implementation of polymer flooding makes three breakthroughs: (1) the first polymer flooding pilot test in offshore oilfields in China; (2) initial application of a hydrophobically associating polymer as the driving agent in the field; (3) significant increment of oil in the trail of a single well injection of polymer. The practice illustrates the feasibility of polymer flooding under current production conditions of offshore oilfields that lead to applications in a larger scale.
Enterprise e-Information Level and Maturity Analysis
Authors: Zhang Dongping , Pen Wei
Published: December 2007

By giving a definition of general enterprise's e-information structure model, each level in the structure is described. A real enterprise's e-information is analysed corresponding to those levels. Based on a standard Information Maturity Model (IMM) that is used in IT industry currently, the special characteristics of five levels in IMM are discussed in detail. According to those features, a real enterprise's information maturity status is introduced. Compared with the theory of IMM, a full-scale analysis is bringing up for this enterprise, such as information maturity, personnel training, traditional thinking, management, IT service, consultant service and evaluation. The highest level in IMM can be achieved in the future if more attention to be paid and existing problems to be resolved.
Maximizing Drilling Performance With State-of-the-Art BHA Program
Authors: Chen David C.-K. , Wu Min
Published: December 2007

This paper presents a state-of-the-art bottomhole assembly (BHA) program using the industry's first generic algorithm based on Lubinski's equations. The strengths of the new algorithm are flexibility and accuracy, as compared to the conventional finite-element based BHA programs. The new algorithm enables several critical features for directional drilling, such as optimal BHA design for maximum directional steerability, bending moment calculations for fatigue analysis, deflection calculations to improve MWD/LWD data quality, BHA sag corrections to improve survey quality, and predict ahead with bit/formation model. In addition to static analyses, the new program incorporates the finite-element method to perform a steady-state dynamic analysis to calculate the critical rotary speeds of the BHA. As a result, users can run static and dynamic models in the same application. This paper describes the significance of applying these features in a user-friendly application to maximize drilling performance.
Porosity and Permeability Estimation by Gradient-Based History Matching Using Time-Lapse Seismic Data
Authors: Dadashpour M. , Kleppe J. , Landrø M.
Published: December 2007

A method based on the Gauss-Newton optimization technique for continuous model updating with respect to 4D seismic data is presented. The study uses a commercial finite difference black oil reservoir simulator and a standard rock physics model to predict seismic amplitudes as a function of porosity and permeabilities. The main objective of the study is to test the feasibility of using 4D seismic data as input to reservoir parameter estimation problems.

The algorithm written for this study, which was initially developed for the estimation of saturation and pressure changes from time-lapse seismic data, consists of three parts: the reservoir simulator, the rock physics petro-elastic model, and the optimization algorithm. The time-lapse seismic data are used for observation purposes. In our example, a simulation model generated the seismic data, then the model was modified after this the algorithm was used to fit the data generated in the previous step.

History matching of reservoir behavior is difficult because of the problem is not unique. More than one solution exists that matches the available data. Therefore, empirical knowledge about rock types from laboratory measurements are used to constraint the inversion process.

The Gauss-Newton inversion reduces the misfit between observed and calculated time-lapse seismic amplitudes. With this method, it is possible to estimate porosity and permeability distributions from time-lapse data. Since these parameters are estimated for every single grid cell in the reservoir model, the number of model parameters is high, and therefore the problem will be underdetermined. Therefore, a good fit with the observation data is not necessary for a good estimation of the unknown reservoir properties. The methods for reducing the number of unknown parameters and the associated uncertainties is discussed.