bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oil Recovery by Miscible SWAG Injection
Authors: Jamshidnezhad M. 
Published: October 2008

Abstract
Previous studies showed that injection of water and gas as water alternating gas (WAG) process or simultaneous water and gas (SWAG) process can improve the sweep efficiency. Therefore, oil recovery from depleted reservoirs can be enhanced by combined injection of water and gas. However, SWAG process compare to WAG process is less known. Investigation of factors that affect on miscible SWAG injection is the aim of this study. For this purpose, a three-dimensional finite-difference reservoir simulator is used. Methane (as gas) at minimum miscibility pressure (MMP) is injected into an under-saturated reservoir which contained typical North Sea oil. Water and gas are injected at fixed rates by two separate horizontal wells. For more sweep efficiency and increase the distance gas and water travel before segregation, gas is injected at the bottom of reservoirs. For water, different locations of injection are tested and the effect of water injection location is studied. We also investigate the effect of water to gas injection rate ratios, well models, and reservoir heterogeneity on sweep efficiency and oil recovery.
An Interpretation Method of Downhole Temperature and Pressure Data for Flow Profiles in Gas Wells
Authors: Achinivu Ochi I. , Li Zhuoyi , Zhu D. , Hill A. D. 
Published: October 2008

Abstract
Accurate and reliable downhole data acquisition has been made possible by advanced permanent monitoring systems such as downhole pressure and temperature gauges and fiber optic sensors. These downhole measurement instruments are increasingly incorporated as part of the intelligent completion in complex (highly slanted, horizontal, and multilateral) wells where they provide bottomhole temperature, pressure and sometimes volumetric flow rate along the wellbore. To fully realize the value of these intelligent completions, there is a need for a systematic data analysis process to improve our understanding of reservoir and production conditions using the acquired data and to make decisions for well performance optimization.
We have successfully developed a model to predict well flowing pressure and temperature (i.e. the forward model), and applied an inversion method to detect water and gas entry into wellbore using synthetic data generated by the forward model (i.e. the inversion model). It is concluded that temperature profiles could provide sufficient information to identify fluid entries, especially in gas wells. However, both the mathematical complexity and advanced well structure lead to challenges in model validation and application. In this paper, hypothetical examples based on previously published field example were used to explain how the interpretation model works. Some parameters used in the model are discussed. Practical guidelines on how to initialize the inversion process and achieve a quick conversion are presented. Judgments should be used based on the understanding of temperature and pressure behavior when initializing the forward model and this can increase efficiency of model application. The study results and guidelines developed in this study will help us to design permanent monitoring systems and set realistic expectation for predictive capability of intelligent well systems.
Field Development Optimization of Siberian Giant Oil Field under Uncertainties
Authors: Volz Richard , Burn Karam , Litvak Michael , Thakur Subhash , Skvortsov Sergey 
Published: October 2008

Abstract
The field development of a clastic reservoir in Siberia has been optimized. Uncertainties in geological description have been incorporated into the optimization process. A reservoir modeling study was undertaken to ascertain the impact of subsurface uncertainties on field production predictions and to evaluate a large range of field development options. Many exploratory wells have been drilled in this field covering a large areal extent. Pressure data from pressure buildup and well interference tests are available from these wells. BP's powerful Top Down Reservoir Modeling technology (TDRM™) has been used for assisted history matching. Multiple geological descriptions matching historical pressure data have been generated. The calibrated multiple reservoir models representing uncertainties in reservoir geology have been evaluated over a large range of field development options and for the definition of uncertainties in future production performance. BP's Top Down Depletion Planning technology (TDDP™) has been used for the optimization of well patterns, well spacing, well types (vertical versus high angle wells), lengths of high angle wells, order of well pad development, etc. The net present value (NPV) of the project has been maximized whilst meeting field development constraints. Thousands of potential field development options meeting field development constraints have been automatically evaluated. Multiple reservoir models have been run for every evaluated field development option to determine uncertainties in future production performance. As a result, an optimized field development option has been proposed with significant incremental net present value and oil recovery in the comparison with the current technical development scheme.
Feasibility Study of Combining Drilling with Casing and Expandable Casing
Authors: Shen Hendry , Aadnoy Bernt 
Published: October 2008

Abstract
Rig cost, service company rates and materials costs have gone up significantly in accordance to the oil price. Industry is therefore continuously searching for new technologies to make the drilling of wells safer, more efficient and economical. This paper will explore the possibilities of combining two existing technologies to meet these challenges.
Drilling with casing (DwC) uses standard casing as the drillstring and leaves it in place to case the well. It has a potential of saving of rig time by eliminating drillstring tripping and also minimizing downhole problems. With expandable technology, expanded casing can provide a larger diameter of the production casing. This can increase the well productivity.
Because both technologies have similar operational procedures, they could be combined into one operation. The new concept is to use expandable casing as a drillstring which will be expanded when the target depth is reached.
The conclusion of this analysis is that the drilling with expandable casing concept is possible. However, there are some technological challenges, especially on tools and on the strength of post expansion materials.
The examples analyzed, indicate that we can save 39% of the operation time by running this combined technology. Expenses can be reduced through lowered rig costs and the operational risk can be mitigated. A better understanding of the technology and operational procedures will help to further reduce the risks and make the technology even more acceptable. If this new method succeeds, there will be a high potential for cost savings, higher production rates and better well control.
Data Architecture of Real-Time Drilling and Completions Information at Saudi Aramco
Authors: Khudiri M. M. , Shehry M. A. , Curtis J. D. 
Published: October 2008

Abstract
This paper describes the current data architecture that Saudi Aramco has recently implemented for real-time drilling and completions (D&C) information. This new architecture enables us to make wider use of our monitoring and collaboration centers through a common approach. It also allows us to leverage the evolving WITSML standard more effectively in our drilling operations.
Saudi Aramco uses many different service organizations to deliver its global drilling and completions agenda. In the past, this has resulted in a lack of stability and standardization in real-time information flow. We have been unable to share data and expertise readily between different operating centers. Applying a common approach to information access on a global basis has enabled us to streamline our operations and make wider use of emerging analysis, monitoring and collaboration technologies.
Real-time technologies have been utilized to capture, monitor and analyze drilling data from rig sites so that critical decisions can be made real-time in order to help reduce and eliminate borehole problems, thus reducing non-productive time. That includes high-tech rigs, business continuity solutions for real-time information, collaboration tools and real-time data visualization systems.
Our aim has been to implement a standard D&C information architecture. Our adoption of WITSML was the vehicle which allowed this to happen. However, we still believe that over the next years it is likely that there will be much more of a challenge to support open connectivity between different vendors and services supporting the increasing drilling and completions functions.
Horizontal Wells - Their Application and Status in Russia
Authors: Gallivan J. D. , Gunningham T. W. , Holtslag R. J. , Kuramshin R. M. , Pepelyaev R. V. 
Published: October 2008

Abstract
Horizontal wells have a long history in Russia in many different producing basins. This paper relies on published sources to give the reader both general and detailed information about the applications, well types and performance which could be gleaned from published articles in Russian journals and books. A period of 60 years is covered, from 1947 to 2007, during which about 3000 horizontal wells have been drilled in Russia. The current rate of drilling is about 300 wells per annum. The paper looks at horizontal wells in four regions of Russia: Volga-Urals, Timan-Pechora, western Siberia and the Far East.
In the early days spectacular improvements in production were reported, in the range 10 to 20, compared with production from vertical wells. Lower improvement factors have been reported more recently in Tatarstan, in the range 1.3-1.6 in limestone formations and 1.5-3.5 in sandstone formations but in one case in western Siberia a factor 10+ improvement was seen. In heavy oil fields the rate improvement factors reported are 5-10. Underbalanced drilling has been tried successfully using oil-nitrogen mixture as drilling fluid. The improvement over horizontal wells drilled with conventional overbalance is 4 times.
It is proposed that an industry-wide data base be sponsored by the Ministry of Natural Resources so that operators could pool their data, establish a set of best practices and cooperate to optimize the performance of wells with horizontal well bores.
Techniques such as:
logging on coiled tubing, well testing with packers and downhole shutin, completions with downhole monitoring and control (smart well completions),
are used in Russia only by a small number of operators. Their benefit is in enabling the operator to check that the well is flowing over its full horizontal length and that the mechanical skin is close to zero. If not then drilling and completion practices need to be improved.
Improved Oil Recovery by Cyclic Injection and Production
Authors: Shchipanov A. A. , Surguchev L. M. , Jakobsen S. R. 
Published: October 2008

Abstract
Cyclic waterflooding is an IOR-method that improves oil production in heterogeneous reservoirs with high-permeability contrast. The concept of the method is based on pulsed injection and alternating of waterflood patterns. The main effect induced by the cycling of wells is oil production increase accompanied by water production decrease. The production increase is achieved by improved sweep efficiency in low permeable zones of a reservoir non swept by traditional waterflooding process. The cyclic water injection process was successfully applied in a number of sandstone and carbonate oil fields in Russia, USA and China. The important advantages of the method are virtually zero additional cost and simple implementation procedure. The uncertainty with the method is related to understanding the IOR mechanism, ability to accurately model the process and design a field application.
The paper presents the results of the study of cyclic water injection and oil production at a North Sea heterogeneous sandstone reservoir. The study consists of the field history analysis, pre-screening cyclic efficiency estimation and numerical reservoir simulation to design the field application of the IOR-method.
The field history analysis shows the presence of cycles in injection and production and their influence on water-cut change. Pre-screening analytical tool was used to perform a wide-range sensitivity analysis with respect to rock-fluid parameters, heterogeneity, cycle length and pressure conditions in order to understand the mechanism and to estimate the IOR potential. Finally the sector model reservoir simulation was used to optimize the cyclic process by alternating the waterflood patterns and to design the field application. The simulations show decrease of water production and improvement of oil production by up to 3% with short time and by 5% with long time cycles.
Water Shutoff Gels Improved Oil Recovery in Naturally Fractured Raman Heavy Oilfield
Authors: Demir M. , Topgüder N. N. , Yilmaz M. , Karakeçe Y. , Ince Y. , Karabakal U. , Gould J. H. 
Published: October 2008

Abstract
Raman field is a naturally fractured limestone reservoir located in southeastern Turkey. The field is a heavy oilfield with 18° API gravity oil and has strong aquifer pressure support. There are about 140 producers and daily oil production is about 6,000 bbl/d. However, average water cut has exceeded 90% in recent years because of the fractures communicating between the aquifer and the oil zone, which required some remedial treatment such as polymer gels to reduce the WOR. As it is well known, gel treatments have become a more convenient method as they can penetrate deep into the reservoir without a complete shutoff.
As a pilot application, deep penetrating gels were used in seven wells. Wells with different behavior were selected as candidates on purpose, in order to see the effect of gel treatments on reducing WOR. The main purpose of the treatments was to increase oil recovery, with water shutoff was considered as a secondary benefit.
Treatments were performed in September 2007. Very favorable results have been seen in the eight months following the treatments. Although gross production rates were generally reduced to get the most benefit from the gel treatments, still, pretreatment oil rates from 0-14 bbl/d were increased to 6-91 bbl/d along with average water cut decrease from 97% to 80%, and even up to 40% in one well. These successful results will also provide the necessary clues for improving the design and field application of gel treatments which are to be extended on a field wide basis in the near future.
Performance Evaluation Of Non-Conventional Wells In Hassi-Messaoud Field, Algeria
Authors: Youcef Boughaba , Kamel Belkhiar 
Published: October 2008

Abstract
Recent developments in drilling field technology allow drilling advanced wells in Algeria oil field. In the past fourteen years several horizontal and multilateral wells have been drilled in Hassi-Messaoud field. In the other hand, the interest in re-entry of existing wells keeps growing. The first goal of such wells is to improve the primary production through increasing the reservoir exposure and accelerating the recovery.
The most important aspects to consider regarding the application of non-conventional wells are the potential cost benefits and potential risks in utilizing the technology. Difficulties exist in predicting the performance of these wells arrangements. Many of the performance prediction difficulties are being addressed through different projects.
Also, these wells can provide means to produce more oil at an economic cost. Applications to actual field cases are provided to illustrate the potential of horizontal and multilateral wells and of their synergy with EOR methods.
This study presents the simulation and the assessment of non-conventional wells in Hassi-Messaoud field, and discusses the factors affecting the productivity of such wells, it confirms the production regime of the reservoir with recovery of 60% by water injection, and illustrates the effectiveness of multi-lateral wells in anisotropic formations, also drilling and production performances for re-entries, short radii and long radii are evaluated. The success in oil rate using long radii can each 93.8% better than re-entries with 80.4% where Long radii wells exhibit a much better behavior than re-entries
In addition, Borehole stability represents a real issue in HMD where the instability may slow down the drilling progress, reduce well rate, and in the worst case it may cause the loss of the whole well, therefore planning non conventional wells should take into account this aspect in addition to reservoir heterogeneity.
Prediction of Oil-and-Gas Bearing Capacity of Low-Permeability Reservoirs within Lower Cretaceous Clinoform Sedimentary Formations in Kondinsky-Priobsky Oil-and-Gas Area
Authors: Kruchkova T. V. , Igoshkin V. P. , Kuklin A. V. , Davitashvili G. I. 
Published: October 2008

Abstract
The article addresses a large area (a territory 100 km long and 80 km wide) encompassing several oil fields, including South Priobskoye, Chaprovskoye, Kondinskoye, Malokondinskoye, North Kondinskoye and West Kondinskoye. The breakdown of this huge and actually a single oil-and-gas bearing zone consisting of a series of sand lenses and containing 1.5 bln tons of recoverable reserves is rather tentative. The authors of this paper have been working in this area and participated in exploration, investigation and development of numerous fields within the Priobsky-Kondinsky zone. Due to complex geology of clinoform formations, low flow properties of the rocks, wide spacing of exploratory wells and seismic surveys, a number of fields situated in the southern part of the Frolovsky depression were brought into production 15 to 20 years later than expected. A significant engineering breakthrough in oil production occurred due to implementation of massive reservoir fracturing treatments and integrated approach to 3D seismic interpretation. These are the technologies that allowed successful development of low-permeability clinoform productive reservoirs within AS9-AS12 formations in all the fields discovered in this area. As of today, a great amount of 3D seismic surveys were shot in many license areas totaling over 3000 sq km. Production drilling and oil production in actually all the fields within the Priobsky-Kondinsky area involve massive frac jobs. Integrated interpretation of 3D seismic led to surprising results indicating the most complex geology of the Neocomian clinoform reservoirs including both tectonic processes associated with sediment slides, and formation of fans within turbide flows. Thorough insight into spatial position and forecasting of flow and storage properties of each sand body allows efficient drilling and development of low-permeability oil saturated reservoirs in the Priobsky-Kondinsky area.
The Use of Ejectors Pulsating at a Late Stage of Developing the Gas Fields
Authors: Slobodkina Francheska , Kadet Valery , Evtjukhin Andrey 
Published: October 2008

Abstract
The eject devices have been known for a long time and are broadly used in various fields of technology for increasing the waste of low-pressure gas be way of mixing it with the steady flow of the high-pressure gas.
The ejectors as jet pumps are successfully used in the chemical, oil and gas industry, in the aero cosmic industry as well as in the technology of electrical stations. The simple design and high reliability of fluid ejectors allows them to meet various demands. Their production cost is minimal; they don't have rotating details and are therefore quite durable. They work without leakage; they don't need the technical testing and therefore have a high production safety. When the active gas has enough pressure the exploitation cost is not high.
In the oil and gas industry when a field is being developed the lowering of the debit of the boreholes is quite a negative phenomenon, especially at the final stage of the exploitation. This happens because of the fall of the layers pressure and the increasing of the water debit, which can bring about the self-stopping of the скважины To avoid these negative things one should switch on the low-pressure скважины into the common gas storing network with the help of an ejector, in which the pressure of the low-pressure gas is increasing at the expense of the energy of a small waste of gas of the high pressure wells.
This allowed to get a considerable additional amount of gas for the already stopped скважины at the Urengoi field. If you switch the ejector devices at earlier stages of the development of the fields the effect of its use can be much more considerable.
Van-Yogan Field: Evaluation of the Optimal Development Strategy for a Thin Viscous Oil Rim with a Large Gas Cap
Authors: Shaykhutdinov Ildar , Galimordanov Vadim , Bardin Valeriy 
Published: October 2008

ABSTRACT
This paper is devoted to the issues related to the strategy of development of an oil-and-gas accumulation of Cenomanian age. Vanyogan field is taken as an example (West Siberia).
Results of the conducted well tests and pilot work to develop a thin and highly-viscous oil rim in PK1-2 reservoirs at Vanyogan field demonstrate that it is impossible to develop this oil accumulation without its separation from the gas cap. Gas breaks through immediately from the gas cap to the producing wells.
One of the possible ways to develop this oil rim is barrier waterflooding.
The system of development via the barrier waterflooding (water injection into the gas-oil contact) may enable conditions preventing gas coning movement towards producing wells. However, to create the water barrier will require significant overcompensation (200-250 %).
Controlled gas production from the gas cap is a possible way to produce oil reserves at immovable GOC (gas-oil contact) and lower voidage replacement ratio. Decrease in initial oil-and-gas reserves ratio by a quarter, may provide lower level of compensation (about 150%) required for barrier forming.
Based on the projected system of development (barrier waterflooding) it is possible to use thermal methods by injecting hot water into a reservoir.
Analysis of simulation results manifests a significant loss of heat during the process of barrier forming due to dominating filtration of the working agent into a gas saturated part of the reservoir that is an evidence of low efficiency of the thermal stimulation.
Results of the steam injection lab studies (fresh water) demonstrate significant swelling of clay in the rock, multiple reduction of permeability and thus impossibility of using these methods in practice.
The optimal way to retain rheological properties of oil is to inject water heated up to the reservoir temperature.
The pilot program is underway to test the barrier waterflooding at the field and assess the efficiency of the thermal method on the representative areas of the accumulation.
Implementation of the program will enable to evaluate technological efficiency of the barrier waterflooding in combination with the thermal stimulation and prepare the object for the commercial development.