bluuebunny/crossref_metadata_2025 huggingface dataset:
Thermal Injection Well Falloff Testing
Authors: Walsh John W. , Ramey H. J. , Brigham W. E.
Published: December 2007

A study was conducted to find field case histories of swept volume determination from pressure transient tests at an injection well. In an earlier study, a pressure transient model of a two-region reservoir was solved analytically and it demonstrated that in principle, both the permeability-thickness and also the swept volume of both regions may be determined. From the model, a typical falloff curve consisted of an initial semilog straight line, a transition period, and finally, a second semilog straight line. The transition period was found to contain a pseudosteady-state Cartesian straight line whose slope was related to the swept volume. Several sets of field test data were examined to verify the existence of the Cartesian straight line.

In order that the swept volume may be calculated from the slope of the Cartesian straight line, the average reservoir pressure and temperature in the swept zone must be estimated. The average pressure is the early-time flattening of the pressure curve on a semilog graph. The average temperature can be estimated from the pressure for steam injection, but requires calculation for combustion. One method involves a heat balance which includes both the heat generated by combustion and heat loss to overburden. Knowledge of the swept volume permits calculation of important economic parameters including the fuel concentration in a combustion test and heat loss in a steamflood.

Several case histories are presented from both in-situ combustion and steamflood projects. An investigation for each case history shows the information that may be obtained from pressure transient tests. Pressure transient testing of the injection well may prove useful in evaluating and controlling the performance of thermal recovery projects.
Application of Relative Permeability Modifiers to Control Water Cut Following Hydraulic Fracturing in Western Siberia Oilfields—Russian Case History Study
Authors: Borodin E. G. , Vakhroushev P. E. , Stolyarov S. M. , Kalfayan L. J.
Published: December 2007

Due to geological characteristics and low permeability of Western Siberia hydrocarbon reservoirs, hydraulic fracturing is the most effective method for improving hydrocarbon production. During recent years the massive fracturing treatments in this area have led to a reduction of well candidates for this type of production enhancement technique. Currently the majority of selected wells for fracture stimulation are considered "risky" because of significant water cut increase after stimulation. The question arises – How to reduce water production while enhancing oil production?

This paper reviews 26 case histories exemplifying the use of Relatively Permeability Modifiers (RPM) in hydraulic fracturing to enhance oil recovery and control water production. Also results of laboratory studies are included to support the RPM-fracturing concept and placement techniques.
A Model for Gas Coning and Rate-Dependent Gas/Oil Ratio in an Oil-Rim Reservoir
Authors: Mjaavatten Are , Aasheim Robert , Saelid Steinar , Gronning Oddvar
Published: December 2007

In oil rim fields a thin oil layer lies between an aquifer and a gas cap. Oil may be produced from such fields using horizontal wells. Production will lower the local gas/oil contact near the well in a process called gas coning (or more accurately, cresting). After gas breakthrough, the gas/oil ratio (GOR) from the well may vary strongly with the production rate. The ability to predict this dependency is essential for production optimisation for such fields.

We have developed a mathematical model that can predict gas coning behaviour and the resulting rate dependent GOR with a surprisingly high degree of accuracy over periods of several months or more. We combine a dynamic model that describes the essential reservoir behaviour with a highly simplified description of the interaction between the well and the surrounding reservoir. The full model has three adjustable parameters that allow us to fit the behaviour to individual wells, using historical oil and gas production rates. The model forms the basis of the GORM (Gas/Oil Ratio Model) computer program that since early 2003 is in regular use for production planning and optimisation at the Troll field. We have also tested the model on wells in other fields, with encouraging results.
Fracturing Treatments of Openhole Horizontal Wells in Western Siberia
Authors: Brovchuk A. V. , Diyashev I. , Lipyanin A. V. , Grant D. , Oussoltsev D. , Butula K. K.
Published: December 2007

In Western Siberia, there is a number of open-hole horizontal wells completed with un-cemented predrilled liners. While many of these wells produced as expected, some wells with horizontal section lengths between 500 to 1100m (effective lengths from 400 to 900m), were producing significantly lower than the offset verticals wells that had been hydraulically fractured with proppant. Decline curve analyses of these under producing wells indicated either high skin value or a limited producing horizontal interval.

Various attempts to increase the production by cleaning up the horizontal section of the wellbore (such as acidizing with CT, implosion treatment etc.) showed only small incremental in PI but did not solve the problem of reducing the skin to zero or lower. Technical limits and large financial and operational expenditures, as well as associated production losses made these types of treatments unattractive.

Detailed analysis of the formation and production data, selection of top-priority candidate wells with employment of technically sound frac designs allowed the operator to implement propped fracturing treatments as a stimulation method in these horizontal open-hole wells. As a performed risk analysis of the stimulation operations was deemed acceptable, hydraulic fracturing treatments were initiated and to date, the 19 propped fracture treated open-hole horizontal wells in Noyabrsk region of Western Siberia (Sugmutskoe and Romanovskoe field) have shown productivity index [PI] increases between 2 to 4.5 folds. This compares favorably to offset vertical fractured wells with S = -5 (1.8 – 3.8 folds).

This paper describes the unprecedented integrated approach in hydraulic fracturing treatments of horizontal open-hole wells with un-cemented predrilled liners as one of alternative completion methods that may be used in horizontal field development projects.
Prop Transport in Vertical Fractures
Authors: Clark Peter Edward , Manning Francis Scott , Quadir Jamal A. , Guler Nihal
Published: December 2007

The subject of prop transport in vertical fractures has been much discussed in the literature in the past five years. Yet, there are many questions that remain unanswered. Probably the most difficult question to answer involves particle transport by cross-linked gels. The major problem encountered in studying particle settling in cross-linked fracturing fluids is the extremely slow settling velocities. This limits the type of experimental apparatus that can be used to closed systems with long particle residence times. The low settling velocities coupled with the difficulty of obtaining good rheological data makes the development of mathematical correlations for the data difficult.

In this study, two different experimental models have been used to obtain particle settling data. One model consists of a parallel plate apparatus in which the shear on the fluid is provided by a moving belt and the other consists of a concentric cylinder device similar to that described by Novotny (SPE 6813). Both of these models are capable of providing adjustable shear rates and long particle residence time necessary for data collection. Data will be presented for both cross-linked and uncross-linked fluids. The viscosities and degree of cross-linking have been varied in order to detect the influence that cross-linking has on particle settling velocities over and above the contribution that cross-linking makes to the viscosity.
Remediation of Production Loss Due to Proppant Flowback in Existing Wellbores
Authors: Nguyen Philip D. , Stegent Neil A. , Ingram Stephen R.
Published: December 2007

This paper presents the results of experimental study and field case histories of a remedial treatment technique using a low-viscosity consolidating agent placed into the propped fractures by coiled tubing (CT) or jointed pipe coupled with a pressure pulsing tool. The treatment fluids are designed to provide consolidation for previously placed proppant near the wellbore without damaging the permeability of the proppant pack. The consolidation treatment transforms the loosely packed proppant in the fractures and the formation sand close to the wellbore into cohesive, consolidated, yet highly permeable packs.

Laboratory flow testing indicates that the proppant pack in a fracture model under closure stress required low-strength bonds between proppant grains to withstand high production flow rates. Field case histories are also presented to discuss treatment procedures, precautions, and recommendations for implementing the treatment process. One major advantage of this remedial treatment method is the ability to place the treatment fluid into the propped fractures, regardless of the number of perforation intervals and their lengths without mechanical isolation between the intervals. The fluid placement efficiency of this process makes remediation economically feasible, especially in wells with marginal reserves.
Linear Gas Drives in High-Pressure Oil Reservoirs Compositional Simulation and Experimental Analysis
Authors: Auxiette Gerard , Chaperon Isabelle
Published: December 2007

This paper presents an analysis of the compositional process involved in the displacement of oil by high pressure gas injection as observed in laboratory experiments. Such an analysis is necessary in order to transpose these results to a field-wide scale for EOR projects.

Therefore a two-fold compositional tool has been developed: The first function handles the Peng and Robinson equation of state to describe phase equilibria of multicomponent hydrocarbon mixtures. Based on thermodynamic considerations it computes either frontal or rear dynamic miscibility pressure as well as direct miscibility pressure of a gas/oil system.The second function simulates linear displacement of oil by gas involving compositional exchanges between phases (also based on P.R. equation of state) and their effect on flow parameters.

Results of this compositional model are checked against laboratory experiments carried out on a field crude oil with three possible injection gases.

This model yields a better understanding of various types of non-equilibrium gas drives and enhanced recoveries related to compositional transfers and mobility variations.

A useful application is to select the most appropriate gas to be injected into a given field under reservoir conditions or after some depletion. It also shows how the notion of gas/oil relative permeability curves should be reviewed if a black-oil model is used to simulate flow of non-equilibrium fluids.
Miscible Gas Enhanced Oil Recovery Economics and Effects of the Windfall Profit Tax
Authors: Bloomquist Charles W. , Fuller Keith L. , Moranville Michael B.
Published: December 2007

The profitability of miscible flooding in a hypothetical target oilfield is examined. The major costs, including Windfall Profit Tax, are identified and their relative importance are discussed. The sensitivity of profit to important physical and economic variables is evaluated and discussed, including variance in oil recovery, oil price, injectant requirements, injectant cost, and capital requirements. Economic sensitivities to important development and operating decisions such as timing. spacing, slug size, and gas recycling are also analyzed. The Windfall Profit Tax (WPT) as it applies to gas miscible EOR projects is reviewed. The effect of WPT on each of the various project cases is analyzed and the effect of reduced WPT on remaining production from existing operations is evaluated. Tax implications are compared for integrated vs. "independent" controlled projects and the alternative of expensing vs. capitalizing tertiary injectants is also evaluated. The impact of the Net Income Limitation in reducing WPT during early and late project life is determined and discussed.
Investments and the Energy Price Revolution
Authors: Roberts Martin C.
Published: December 2007

The quantum jump in crude prices which we have expoerienced over the past seven years has had an extraordinary impact on the economic, social and political well-being of the world. That impact is evidenced in the way in which investors perceive the equity markets, a perception that now appears to oscillate between euphoria and dischantment over a relatively short period of time.

The reason for this short-term "bullish and bearish" attitude appears to be the uncertainty brought about by (1) the impact of the magnitude of the crude price increases on existing technologies, and (2) the change in supply/demand relationships for the crude itself.

With regard to the former, rapidly increasing crude oil prices have made the western world's plants and processes essentially obsolete, an obsolescence due to their energy intensive processes and configurations, which were designed to run on relatively inexpensive fuels. Consequently, we are now witnessing the refinancing in the U.S. of its industrial plant, (e.g., revamping of refining facilities, retooling of automobile manufactturing, and a potential emergence of a synfuel industry.) Obviously, the uncertainties associated with the timing, financing and technology of these changes raise serious questions in the minds of investors cocerning the degree to which these investments will be capitalized in the market place.

The second issue of uncertainty has to do with the crude oil supply/demand relationships, which have changed substantially over the past seven years. Classic supply/demand relationships do not necessarily hold for a political, price administered commodity like crude oil. The international oil trade has undergone considerable structural changes so that today about 80% of world crude reserves and 20% of the volume sold are controlled by national oil companies--just the reverse of 10-15 years ago. Consequently, those who are forecasting surplus conditions and who are advocates of the "glut thesis" are failing to come to grips with the fact that the incremental worldwide crude supplies are derived from a portion of the world in which the supply lines are long, tenuous and subject to interruption for reasons that can be economic, political or social. The high degree to which the world depends upon these insecure, expensive incremental crude supplies seems to preclude a forecast of long term surplus supplies and downward price pressures.

The investment implications of insecure, expensive foreign crude supplies coupled with an attempt by the western industrialized world to modernize its plant appear to involve uncertainties which span the entire spectrum from the geopolitical aspects of the international oil trade to commercialization of emerging technologies. In the final analysis, it seems that. the 1arge, secure, albeit costly, U. S. technological and resource base would encourage long term investments in those domestic industries that will benefit from an expanding natural resource base and/or emerging technological base.
A New Correlation of Vapor-Liquid Equilibrium Ratios Internally Consistent With Critical Behavior
Authors: Lawal A. S. , Silberberg I. H.
Published: December 2007

Equilibrium ratios (K = Y/X) for calculating vapor-liquid equilibrium states have been correlated as functions of pressure, temperature, and convergence pressure for the normal paraffin hydrocarbons from methane through decane, isobutane, isopentane, nitrogen, and carbon dioxide. The functions were designed to yield K = 1 at the convergence pressure but, in the interest of more general application, were not subjected to the other constraints associated with binary systems. Convergence pressures were determined by the critical composition method, using previously developed critical locus and critical pressure correlations.

A linear least-squares routine was used to fit the K-functions to 17,245 published experimental equilibrium states in binary, ternary, multicomponent, and complex systems covering a range of temperatures from − 280°F to 700°F, pressures to 12,000 psia, and convergence pressures to 23,200 psia. For the fourteen components, the average absolute deviation of the predicted K-values from experimental is 5.1%.

A model is proposed which relates the derivatives of the K-functions at convergence to the isothermal critical composition locus of the system and is found to give very reasonable results for binary and ternary systems and two multicomponent mixtures. A vapor-liquid phase-equilibrium algorithm incorporating this locus into the convergence pressure calculation was used to compute equilibrium phase compositions for comparison with experimental data from selected binary, ternary and multicomponent systems.
Horizontal Stress Magnitude Estimation Using the Three Shear Moduli—A Norwegian Sea Case Study
Authors: Sinha B. K. , Vissapragada B. , Renlie L. , Skomedal E.
Published: December 2007

Formation stresses play an important role in geophysical prospecting and development of oil and gas reservoirs. A reliable in-situ stress determination is a premise for all geomechanical evaluations of a reservoir including initial drilling, infill drilling, sand prediction, stimulation and fracturing, well integrity evaluation, coupling with reservoir flow analyses, fault reactivation and environmental aspects particularly related to injection. The underlying theory behind the estimation of formation stresses using borehole sonic data is based on acoustoelastic effects in rocks. Acoustoelasticity in rocks refers to changes in elastic wave velocities caused by changes in pre-stress in the propagating medium. Elastic wave propagation in a pre-stressed material is described by equations of motion for small dynamic fields superposed on a statically deformed state of the material. These equations are derived from the rotationally invariant equations of nonlinear elasticity. However, shear wave propagation in a triaxially stressed rock can also be expressed in terms of the stress-dependent shear moduli. A new Stress Magnitude Estimation (SME) algorithm yields the maximum horizontal stress magnitude using the three shear moduli outside the near-wellbore altered annulus together with the Mechanical Earth Model that provides the overburden stress, pore pressure, and minimum horizontal stress as a function of depth. The maximum and minimum horizontal stresses can also be obtained from a multi-frequency inversion of cross-dipole dispersions in the presence of stress-induced crossovers. Inversion results for the stress magnitudes are obtained together with the stress coefficients of velocities in terms of the formation nonlinear constants referred to a local reference state. Formation stress magnitudes together with stress coefficients of velocities help in distinguishing radial alteration of shear slownesses caused by near-wellbore stress concentrations from those resulting from plastic yielding of rock. The methodology used in the two Norwegian Sea wells, operated by Statoil, successfully estimated the horizontal stress magnitudes. Results for the minimum horizontal stress corroborate well with the stress magnitude estimated from extended leak-off test in one of the wells.
Applications of Measurements While Drilling
Authors: Tanguy D. R. , Zoeller W. A.
Published: December 2007

A Measurement While Drilling (MWD) system is now available to provide more downhole measurements than ever before. The measurements currently made near the bit, while drilling is in progress, include: formation radioactivityformation resistivityannular temperaturedownhole weight on bithole deviationazimuthtool face angle

These geological and engineering measurements are transmitted via a continuous pressure wave through the mud inside the drill pipe. The signals are detected at the surface, where they are processed by an on-site computer. Information is plotted in real time on continuous multi-scale logs, presented digitally on video displays, printed out in hard copy, and stored on magnetic tape.

This paper briefly discusses the MWD system that provides these downhole measurements in real time during drilling. Citing actual logs, the paper focuses on specific examples of how these measurements are being used to aid in formation evaluation and to improve drilling control at the well site.
Wells Producing Commingled Zones with Unequal Initial Pressures and Reservoir Properties
Authors: Larsen Leif
Published: December 2007

Pressure and flow-rate transients caused by differences in initial pressures of individual zones in multilayer no-crossflow systems are determined, and effects on drawdown and buildup behavior are investigated. Skin factors are included through the use of apparent wellbore radii. Moreover, methods for estimating reservoir parameters from pressure transients prior to production are presented. A special method for estimating the flow capacity of each zone in two-layer reservoirs from long buildup tests is also included.
A Multi-Objective Economic Analysis of Oilfield Production Policy
Authors: Harrison G. H. , Tweedie J. A.
Published: December 2007

With reference to contemporary changes in the structure of the international oil industry, it is demonstrated that circumstances may prevail under which multiple and conflicting economic objectives can confront participants in the development of an offshore oilfield.

An analytic frame-work is presented to facilitate the choice of a development strategy which incorporates a trade-off between conflicting objectives where they exist.
Fracture and Vuggy Porosity
Authors: Weber Koenraad Johan , Bakker Margot
Published: December 2007

The discovery of hydrocarbons in fractured rock always brings up the controversial subject of fracture porosity. Evidence of brecciation, leaching and infilling often complicate the issue. The high recovery efficiency of oil from fractures combined with the frequent absence of appreciable matrix porosity, in many cases enhance the economic importance of the estimated figures.

Sometimes one can base ones predictions on local production experience from similar fields, but more often one has to rely on the limited information from production tests, cores, logs and occasionally nearby outcrops. At an early stage this approach can only lead to the location of the most fractured or vuggy zones and a very rough estimate of the associated porosities.

To reduce the uncertainty one can make use of a statistical approach based on a classification of fractured reservoir types with corresponding porosity ranges collected from literature. An attempt has been made to gather a comprehensive worldwide data suite large enough to establish reliable porosity ranges for a series of reservoir types.

A simple practical classification into seven types of fractured and leached reservoirs has been adopted based on tectonic style and leaching processes. Any figures quoted in literature were critically examined and only used when there was clear evidence that they were based on thorough fracture/vug spacing and fracture/vug width and size studies or on reliable material balance calculations. This reduced the data set to a fraction of its original size but the resulting table is thought to stand up to scrutiny.
Implementation of Internal Environmental Audit in TNK-Nizhnevartovsk as a Means to Improve the Environmental Management System.
Authors: Chernushenko Galina A.
Published: December 2007

To improve the Company's image and, also, its attractiveness for Russian and foreign partners and investors due to its stable HSE parameters, and for development of a system approach to reduction of use of materials and power resources in the Company, development of the Environmental Management System (EMS) was started in 2003, in accordance with ISO 14000 international standards.

Within 2005 the Environmental Management System was introduced in full and the certificate on compliance with the international standard was acquired.

One of the key provisions of ISO 14001 international standard (the adherence to which is evaluated during the certification procedure) is development and maintenance of programs and procedures of periodic audits of the Environmental Management System.

The requirement to "introduce and maintain a record-keeping procedure for periodic evaluation of compliance with environmental legislation and regulations" is another important concept of the standard.

Internal Environmental Audit is a management tool, the integral part of the Environmental Management System, applied for evaluation of EMS performance and timely adjustment of its elements.

Together with other tools providing feedback in the management system (inspections, monitoring, reports, requests of external bodies), Internal Environmental Audit also ensure performance of the Environmental Management System and compliance of the company with governmental requirements to crucial environmental aspects of its activity.

Key Goals of the Internal Environmental Audit: Providing the initiators of audits with true information on environmental aspects of the Company activities and providing for compliance of this information with existing standards, norms and requirements.Elaboration of useful recommendations for the further improvement of environmental management, controlling, etc. and, for increase of efficiency of environmental activities.

Internal Environmental Audit data are used for: Adjustment and revision of the EMS (with involvement of company and division managers);Day-to-day adjustment of the Environment Management Program aimed either at implementation of cost-free or low-cost activities or at generation of EM Program elements for the next target period;Development of corrective (preventive) measures and actions, aimed at compliance of the company with governmental requirements to crucial environmental aspects of its activity.
Exploration Drilling in the Russian Far East: Two Years of Experience and Learning Offshore Sakhalin Island
Authors: Thorogood J. L. , Hogg T. W. , Kalshikov A. G.
Published: December 2007

An exploration well drilled by a joint venture between Rosneft and BP in the summer of 2004 was the first success after a long period of no exploration activity. It represented a step out into a new and untested exploration play.

Wells in Sakhalin involve a permitting cycle that lasts for 7 months and a logistical supply chain that extends 3,500 miles back to Singapore, Figure 1. The sea ice-free weather window lasts from late June until mid-November, with severe storms building from September onwards. Environmental restrictions stipulate that all mud and cuttings from below the 30" conductor, even though the well may be drilled with a water-based mud, cannot be discharged to the environment and must be recovered for disposal.

The team overcame a wide range of organisational, logistical, regulatory, environmental and technical challenges to drill the well in the summer of 2004. Despite the highly compressed schedule, the operation was conducted with no harm to people or damage to the environment. The lessons learned were consolidated and formed the basis for a successful season in 2005 with a different rig.
Prediction of Gas-Saturated Formations of Kharasaway Field From Dynamic and Kinematic Reflected Wave Parameters
Authors: Kuznetsova O. G. , Kuznetsov V. I.
Published: December 2007

Demonstrated is high efficiency of seismic-wave parameters application to qualitatively predict oil-and-gas bearing fields by the example of a sequence of producing layers of the Kharasaway field, Western Siberia, Russia. The involved techniques of productivity prediction enable to quickly define potential fields without application such complex types of analyses as AVO-analysis, seismic inversion, etc.
Improved Cyclic-Steam Well Treatment With Employing Thermoreversible Polymer Gels
Authors: Altunina Lyubov , Kuvshinov Vladimir , Stasyeva Lyubov
Published: December 2007

To increase the efficiency of cyclic-steam treatment of high-viscosity oil pools we propose to use thermoreversible gel-forming polymer systems with lower critical dissolution temperature (LCDT). Presented are the results of laboratory research of thermoreversible gel-forming systems with LCDT: cellulose ether – aqueous phase in the temperature range of 20 – 250 °C. The studies carried out on kinetics of gelation and rheological properties demonstrated repeatability of gel rheological parameters at cyclic reversal of temperature conditions. The action of additions increasing temperature of gelation was determined to be additive. The temperature of gel conversion into liquid is 30-50 degrees below than that of gelation. The indicated temperatures linearly increase with additive concentrations and for all reagents under study except carbamide these dependencies are cymbate. Gel-forming systems (GFS) proved high efficiency on heterogeneous reservoir models, where seam permeability differed 3-5 times, under the conditions simulating operation of a cyclic steam well. We can recommend GFS application to regulate filtration flows of reservoir fluids and to increase conformance of cyclic-steam treatment of high-viscosity oil pools. In October 2005 GFS were successfully injected into two cyclic steam wells in high-viscosity oil pool in Lyaokhe oil field (China).
Evaluation of Upending Operations
Authors: Sekita Kinji , Sakai Makoto , Kato Teruo
Published: December 2007

Offshore structures towed to a job site must be launched and upended (see Fig. 1). 1), 2) In relatively shallow water, a structure is upended by hoisting it with a derrick crane. In deep water, however, a structure (usually large and heavy) is often self-upended without the aid of a crane, through buoyancy adjustment.

There are two important factors involved in upending procedures: the stability of the structure being upended, and the time-dependent change in the attitude of the structure.

A computer program was developed to systematically analyze the stability of a structure being upended. The upending of a hydraulically unstable structure was analyzed by this program and, as a result, a safe upending procedure has been determined.

A flooding analysis method has been developed for the time-dependent attitude change. This method analyzes the time-dependent change in the surface of water flooded into a structure's flood tanks. An actual jacket structure was analyzed by the method, and the analytical results are reported in this paper.
A New in Phase Transformations on Gascondensate fields development
Authors: Abasov M. T. , Abbasov Z. Ya. , Fataliev V. M. , Gamidov N. N. , Mammadova G. H.
Published: December 2007

The work presents results of experimental and analytical investigations enabling to comment on some aspects of phase transformations taking place in natural hydrocarbon systems during the development of deposits.

The following issues have been considered: –A new phenomenon in phase transformations of gascondensate systems and its experimental investigation;–Experimental investigation of the influence of different composition gases solubility in hydrocarbonoceous condensates on the exploration of gascondensate pools; -Impact of the porous medium on the evaporability of condensate while affecting it by "dry" hydrocarbon gas.
Specification of Reservoir Filtration System Model for Talakansky Field on the Well Test Basis
Authors: Diyashev R. N. , Fedorov V. N. , Iktissanov V. A.
Published: December 2007

To create oil field development projects, to make technological decisions for improved oil recovery of gas and oil Talakansky Field and to supply data for reservoir simulation it is necessary to have full and trustworthy information about model of reservoir filtration system.

To gain the goals the well test of inclined-directed and horizontal wells of Talakansky Field have been carried out and interpretation of the results have been made.

It is marked, that almost for the half of the wells the greatest level of concurrence of experimental and calculated pressure values and a logarithmic derivative is achieved by using of Warren-Root model. Zones with various types of collectors are allocated.

Moreover there are determined: presence of impenetrable boundaries on various distances from separate wells, display of a gas cap and distance up to it from various wells, presence of the fractures crossed with separate wells.

The received results specify and supplement the initial information on model of reservoir filtration system of Talakansky Field.
Geological Aspects and Oil-and-Gas Content of Board Pricaspian Syneclise
Authors: Guzel Bakhitova
Published: December 2007

Pogodaevo-Ostaf'evsky depression is situated in northern board of Pricaspian syneclise. It is unrequited late devonian – tournaisian depression, which succeed to ancient Perelyubskiy depression of basement. This depression is filled up by strong (400 m) terrigenous deposits vezenian age (kos'vinsko-radaevskie deposits). On territory of Pogodaevo-Ostaf'evsky depression oil-and-gas fields not yet discovered, but on nearby territory are finded oil inflows from similar sediments. Prospects of oil-and-gas content of depression are connected with three complexes: late devonian – tournaisian, kos'vinsko-radaevskij, and probably, bobrikovian. Opening of oil-and-gas fields in an onboard zone of depression is connected with reefs bodies late devonian – tournaisian age.

Also prospects of territory should be connected with zones of beds thinning on depression board's vezenian thicknesses of compensation. These deposits can be perspective and in an internal zone of depression where their thickness is increased. Conceivably, bobrikovskie deposits have oil-and-gas content (by analogy with Muhanovo - Erohovskij depression where bobrikovskie sandy layers have oil-and-gas content) are presented by covering structures above barrier reefes.

At present by seismic data have been evolved perspective objects on Zapadno – Ovchinnikovskoj, Ovchinnikovskoj, Lebedevskoj, Malozajkinskoj, Novotrudovoj, Severno – Talovoj, Talovoj, Yuzhno – Talovoj areas. These are the bodies of the small size located in a zone of reef benches. Reseched territory – northern board of Pricaspian syneclise, zone of a joint it's with Volgo-Ural'skaya anteclise. Late devonian - tournaisian reef bench, traced in the given territory, on a significant extent it is regressively built on by the vizenian-bashkirian barrier, and they create uniform sedimentary bench. This barrier reef forms boards of Pogodaevo-Ostafevskij not compensated paleodepression, inheriting Perelubskij sag of the base.
Recent Approach to Full Field Comprehensive Reservoir Development Design
Authors: Manapov Timur F.
Published: December 2007

The article covers the main problems related to oil field designing process in Russia. Contemporary field development is characterized with new effective technologies and at the same time deterioration of current recoverable reserves structure, "ageing" of fields. The quality of design documents preparation under these circumstances is a very critical issue.

According to the Russian legislation FDP is the law mandatory for implementation by operating company. However the current state of the quality of design documents and efficiency of the design solutions implementation is far from being perfect. The main reasons are the following: –lack of efficiency in interaction of the state, oil companies and scientific centers during design documentation preparation process;–non-optimum use of geological and field information available, poor data quality;–issues with pay zones modeling and monitoring;–conflict of interests between business representatives (companies) and the state;–organizational issues with scientific centers activity (design institutes).

We need to take comprehensive approach to solve these not simple issues which require actions to be taken by all the interested parties (the state, oil company, design institution). The following actions are suggested as first steps: –ensure more rigid state control of the qualification of the specialists working in design institutions (for example, through licensing designing activity);–set more realists deviations of actual oil production from design volumes than they are now;–introduce special commission body in the state organization to estimate efficiency of physico-chemical technologies of oil recovery enhancement;–ensure mandatory determination of acceptable deviation range of the model before reservoir development modeling (depending on the complexity of issue and the quality of the input data);–provide the opportunity for oil companies to vary the list of wellwork types within the design period if the design principles for reservoir development are followed and final oil recovery factor is not less than the one planned in the FDP;–make technical training of the specialists one of the high priorities for design institution activity (the main focus should be made on standardization of technical knowledge and training process control).
Main oil pipelines technical condition inspection and monitoring
Authors: Pekarnikov N. N.
Published: December 2007

Experience of Open Society of the TDC "Diascan" in enchancement and development of systems of monitoring and provision of safe operation of the main oil pipelines of Company " Transneft" is summarized. Its basis is an increase of efficiency of in-line inspection of Main Oil pipelines (MO) acquiring the more comprehensive data on detected defects while combining the data from different types of ILI and fulfillment of AFS, detection of the combined defects, finding out the criteria while running the flaw detectors on a testing loop, improvement of methods of interpretation; development of new software for processing of the data, the analysis and issuing of the reports; analytical and statistical research of a technical condition of MO system on the basis of the use of "Defect" database and of "Expert" software package; carrying out of tests of pipes with defects for strength and durability to improve the normative documents on technical condition assessment, repair and certification of MO.
Overview of Exploration for Petroleum in Malaysia under the Production-Sharing Contracts
Authors: Said Ahmad
Published: December 2007

The paper discusses the exploration efforts and successes achieved in Malaysia under production" sharing contracts in the 5-year period from 1977-1981.

At the end of 1976, PETRONAS signed 5 production-sharing contracts with SHELL and ESSO for areas offshore Sabah, Sarawak and Peninsular Malaysia. In the 5-year period, over 52,900 line-km of seismic were acquired and 202 exploratory and appraisal wells drilled, resulting in 45 new hydrocarbons finds of significance.

Most of the oil and gas finds were made in the Tertiary sediments of the Malay Basin which had been relatively unexplored prior to 1977. 03 and gas finds were also made in the relatively more mature and geologically more complex exploration provinces of Sabah and Sarawak. The J4 discovery in Sarawak opened up a new precarbonate exploration play in the Central and SW Luconia and NW Balingian Provinces.

The high level of exploration activity has resulted in a substantial increase in Malaysia's remaining petroleum reserves. The 5-year period has also seen the emergence of the Malay Basin, offshore Trengganu as the most prolific hydrocarbon province in Malaysia to date.
Future Hydrocarbon Prospects in Afghanistan
Authors: Tate Robert B.
Published: December 2007

The geology of Afghanistan is described in relation to hydrocarbon occurrence and future potential. Current gas production, exported to Russia, is abstracted from structural closures in Cretaceous — Neogene sediments on the margin of a Neogene — Recent depression northwest of the Hindu Kush mountain range. Source rocks are thought to be Jurassic paralic sediments and/or Cretaceous platform limestones, the latter outcropping extensively across much of central Afghanistan north of the Herat fault zone, a major fracture separating two tectonically different regions. Future exploration should be directed towards the search for similar structural closures with other Neogene — Recent depressions bordering the Hindu Kush, particularly in the north and west.

Substantial thicknesses of Mesozok and Paieogene clastic and calcareous successions are reported to occur in the southern part of the Katawaz fault block, a geotectonic unit between two major fracture zones in SE Afghanistan. Aeromagnetic and field studies indicate a basin up to 9000m thick containing suitable source and reservoir rocks but tight folding, lack of seal lithologies and excessive depth of erosion lessen the chances of finding hydrocarbon pay zones.

Future discoveries are more likely to be gas than oil as the geothermal gradient, both present and historis is thought to be high in view of the tectonic position within a collision zone. Nevertheless, oil seeps, bitumen and fetid limestone in central and western Afghanistan suggest dissociation may not be complete.
Compressible Cement Slurry Helps Solve Annular Gas Flow
Authors: Ott William K. , Miller Gene Warren , Sutton David L.
Published: December 2007

Annular gas flow following cement has been a problem in many areas throughout South-East Asia. In some offshore fields, gas migration occurs on surface, intermediate and production casings and liners. This phenomenon gives rise to gas pressure on the annulus between casings or even interzone communications. Both can cause costly remedial repair work and unpredicted high volume flow to the surface has on occasions caused catastrophic disasters.

Laboratory testing and field applications in many areas of the world have shown compressible cement slurries to possibly be the most effective means of helping to prevent annular gas flow developed thus far. This paper will review the development and application of compressible cement slurries.

Over 800 compressible cement slurry applications have been run throughout the world and the success ratio is greater than 90%. Applying this technique on a more wide-spread basis may possibly reduce the many problems associated with annular gas flow in South-East Asia.
Tubing Buckling Analysis With Expansion Joints
Authors: Mitchell Robert F.
Published: December 2007

A new type of tubing completion in use in the North Sea is a fixed packer with an expansion joint several joints upstream of the packer. The expansion joint installation may be either pinned closed, or sheared and spaced out after packer installation. The joint may or may not have a stop to prevent jump-out. If the joint is pinned close, then a shear rating must be specified for the shear pins. Additional information necessary for expansion joint analysis includes the joint stroke length, joint seal bore diameter, and installation space out, if sheared.

There are distinct differences in the analysis of expansion joints compared with conventional packer installations. This paper details the tubing movement and stress calculations for both pinned and sheared expansion joints. The pinned joint is designed to fail at a specified tubing load, either compressive or tensile. After pin shear, the tubing has free movement until the joint closes, jumps-out, or is restrained by a stop. The sheared joint movement calculation is distinct from conventional tubing movement calculations because there are two piston loads, instead of only one in a free packer. The tubing below and above the joint may buckle. Bending as a result of buckling may cause binding and friction loads in the expansion joint.

This paper presents several example cases that give insight into the potential benefits and problems of expansion joints in comparison with conventional tubing completions.
A Systematic Approach to Drilling and Delivering Wells in Severely Depleted Sands at Ram Powell (GOM)
Authors: Algu D. R. , van Oort E. , Landgrave S. , Grant L. , Hillburn D.
Published: December 2007

Re-development drilling at Shell's Ram Powell prospect in the Gulf of Mexico targets profitable delivery of remaining hydrocarbons present in lower-volume reservoir pockets. Marginal economics put a strong focus on efficient operations, which are complicated by the technical challenges posed by severely depleted reservoirs (up to 6,000 psi differential pressure) that can only be accessed by drilling extended reach (ERD) wells. Specific challenges that had to be overcome in drilling recent Ram Powell wells include negotiating very narrow drilling margins, preventing major non-productive time associated with well control, lost circulation and stuck pipe events, and drilling the wells at optimum efficiency and favorable economics.

This paper discusses the integrated operational plan that the Ram Powell team employed to successfully drill four recent ERD development wells and two slim hole sidetracks through substantial depletion while becoming one of the best-performing offshore operational teams in Shell. Specific tactics discussed include: (1) a fit-for-purpose hole cleaning program for ERD and depleted wells; (2) a mud weight and ECD strategy that exploits the naturally existing stress cage; (3) an effective method to raise fracture propagation pressures in case of losses in induced or natural fractures; (4) the use of flat-rheology synthetic-based mud to minimize barite sag and reduce ECDs; (5) addressing the underestimated effects of temperature, annular pressure fluctuations and exposure time on wellbore stability and lost circulation; (6) contingencies to deal with well control issues during a catastrophic loss; (7) dealing with detrimental vibrations during depleted sand drilling
The Application of Expandable Tubulars in Casing While Drilling
Authors: Gupta Yash , Banerjee Sudeepto N.
Published: December 2007

The idea of drilling single diameter wells has been debated for a number of years. And in recent years, the dream of mono-bore wells is taking form thanks to the development of new technologies. The use of expandable tubulars and the drilling with casing system are the most favoured processes.

This paper discusses the possibility of coagulating these two technologies in an attempt to achieve maximum economic and productive efficiency. The system consists of the usual assembly for drilling with casing, which uses the top drive mechanism, and an expansion cone (mandrel) installed above the drill lock assembly. The expansion cone is operated from the surface through the rotary table. The operation involves drilling to the casing depth using the drilling with casing assembly, and then bringing the expanding cone into action. The expansion procedure starts by conditioning the string and pumping in the expanding fluid through the expansion mandrel. It is caught in the area between the mandrel and the drill lock assembly by closing the bypass valves in the latter. Thus the pipe joints above the drill lock assembly are expanded by the normal procedure, till the mandrel reaches the surface. The mandrel is pulled out, and subsequently the drilling with casing BHA is retrieved by a wireline.

This procedure makes use of the economic savings achieved in case of drilling with casing and the productive maximisation which is achieved for expandable tubulars. By using the expandable tubulars at shallow depths, more casing strings can be accommodated resulting in production of deep formation(s). This procedure also involves a reduction in time related to tripping operations which was earlier associated with the drill string assembly.

More importantly this new technology finds it major application in extended reach deep water drilling, where ultraslim wells need to be drilled to reach the formation. This technology requires a class three or four drilling vessel instead of a conventional class five vessel, thus reducing the drilling costs substantially. These two technologies are currently being used in independent fields and there is no published evidence about the combination of these two operations. Now as this method is researched further, new and more improved versions of the same can be developed.