bluuebunny/crossref_metadata_2025_split huggingface dataset:
Study on Reorientation Mechanism of Refracturing in Ordos Basin—A Case Study: Chang 6 Formation, Yanchang Group, Triassic System in Wangyao Section of Ansai Oil Field
Authors: Li Peichao , Song Zhenyun , Wu Zengzhi 
Published: December 2007

Abstract
The essence of fracture reorientation of refracturing is rock failures. Therefore, the study on reorientation mechanism should be started from studying rock failures, taking the influences of objective and subjective factors such as reservoir microfracture distribution, geostress field, rock mechanics characteristics, physical properties and the methods of well-completion, injection/production, hydraulic fracturing technology upon fracture reorientation into account.
As a result, the conditions that rock failures occur were analyzed, thus the theory criteria for fracture reorientation was given, namely the critical bottomhole pressure required and the conditions which the geostress field and rock mechanics parameters should have. The new fractures are divided into shear fractures and tensile fractures, which correspond respectively to the two kinds of rock basic failure mechanisms-shear failure and tensile failure. The azimuths of these two kinds of fractures are both different from the initial hydraulic fracture (abbr.IHF), and the critical pressure is the function of the geostress field and rock mechanics parameters. Based on the above criteria, utilizing the refracturing data of Chang 6 formation, the feasibility of fracture reorientation for Wangyao section was investigated. And three typical wells were analyzed in details, which show the refracture characteristics we predict accord with that of microseismic monitoring or the curve of the treating pressure.
It indicates that even if the geostress field keeps unchanged, fracture reorientations can be achieved by other ways.
In the certain range of parameters for reservoir physical properties, if a proper fracturing technology, such as TSO (i.e. Tip Screen Out) with temporarily blocking treatment (abbr.TBT), can be applied so as to create the treating conditions that meet the demand of the above criteria, the refracturing can produce new fractures in Wangyao.
And for refracturing treatments, with the shot holes along the IHF azimuth blocked effectively, multi-fractures and new fractures can be achieved by oriented perforations.
Steerable Motors Hold Out Against Rotary Steerables
Authors: Warren T. 
Published: December 2007

Abstract
A decade after field testing the first modern rotary steerable systems, steerable motors still command more than 80% of the directional drilling market. While rotary steerable systems offer a significant technical advantage over steerable motors and provide an enabling technology for many wells, economic forces may moderate their current high growth rate. The realities of balancing system performance, directional program complexity, cost, and risks often dictate bypassing this "latest and greatest" technology.
Evolutionary improvements in steerable motor power, reliability, and operational techniques have allowed them to maintain a healthy competition with the more capable, but more expensive, rotary steerable systems. Operators encourage service companies to provide less costly rotary steerable solutions, but for the short term, the best solution for many wells is still to use the old tried and true steerable motors.
Guidelines to Successful Dewatering of CBM Wells
Authors: Bassett L. 
Published: December 2007

Abstract
Introduction
Pumping water from a well is a straight forward effort that has been done for centuries. Pumping fluid from relatively shallow wells should be an easy task. Normally a pump is installed in a well, started and then forgotten. This premise does not hold true in CBM wells. In CBM wells, this pumping process can be complicated by many issues unless precautions are taken. This paper is designed to address the basic precautions that can be taken to improve de-watering of CBM wells. These precautionary steps can save the operator money by reducing the month to month maintenance associated with CBM wells. Although we cannot cover every potential pitfall to de-watering operation, the basic steps discussed will identify potential problems and offer ideas to address them.
Well Planning for Artificial Lift
The successful de-watering of CBM wells, especially Coal Bed Methane (CBM) wells takes some planning before the first well is dilled. Many factors should be taken into consideration so that the operation can be economical for the entire life of the well. Unconventional gas has gone from an experiment to a logical and viable energy source. Pre-planning can and will reduce the overall cost of operation over the life of a CBM well. Short cutting the pre-planning stage can often take perceived savings in well drilling costs and transfer these costs to much higher day to day maintenance costs and lower gas production, thus decreasing the economics of the play. The learning curve has been steep for operators and suppliers as well as we all try to find solutions to the many challenges that face the industry.
The first step is to identify the type of coals to be de-watered by asking these questions. Are the cleats in the coals easily fractured? How thick are the coals? Do the coals contain sand, clay or other solids that could interfere with pump operations? Are their multiple coal zones and what kind of material separates the zones? Are their other CBM wells producing from the same formations and what problems have they encountered? Pre-planning will reap benefits in lower operating costs and maintenance and higher profitability for the operator.
KPIM of Gas/Condensate Productivity: Prediction of Condensate/Gas Ratio (CGR) Using Reservoir Volumetric Balance
Authors: Olaberinjo A. F. , Oyewola M. O. , Adeyanju O. A. , Alli O. A. , Obiyemi A. D. , Ajala S. O. 
Published: December 2007

Abstract
Accurate forecasting of condensate well deliverability usually requires good knowledge of the gas condensate vapor – liquid properties. Condensate well deliverability is particularly important as it impacts downstream issues such as the number of wells required, surface gas handling facilities, drilling schedules and income from gas sales contracts.
A new approach for forecasting viability of gas condensate wells and calculating condensate gas ratio (CGR), using simpler techniques is presented. The calculation uses a volumetric balance model for reservoir system, standardized and modified correlations, equation of state and a vapor-liquid equilibrium technique. The technique has been extended to include mass transfer and also to allow for the changes in produced fluid composition due to the formation of the condensate bank.
The approach will provide a useful tool for rapid forecasts of condensate well performance, for examining the effects of condensate blockage in different well types or for studying sensitivities. It is also valuable where simple models of condensate reservoir performance are required for use in integrated studies.
An Applied Mathematics Method of Formalizing the Comprehensive Approach to the Evaluation of Reservoir and Well Completion Characteristics
Authors: Spivak S. I. , Yulmukhametov D. R. 
Published: December 2007

Abstract
The determination of petrophysical properties of oil reservoirs is complicated by the limited volume of investigation of the heterogeneous object under study (about 10−6 of the total volume) and the indirect nature of the information obtained. For each property several ways of determination exist, giving values differing sometimes by 1–2 orders of magnitude. One of the principal causes of such discrepancy is the that the problems of property determination using conventional methods are ill-set.
The issues of solving ill-set problems are investigated in the special mathematical theory, which has a lot of applications in natural science generally and in petroleum science in particular. Many problems of reservoir characterization and simulation are ill-set as well; a priori information and multicriterial approach are used in there solution. These are very complex problems, for example, flow model history matching and seismic interpretation. However, the formal multicriterial approach is not well developed with respect to relatively simple tasks of geology, petrophysics and reservoir engineering, such as permeability determination from well logging data, and others. The purpose of this work is the formalization of comprehensive approach to the solution of such problems.
The problem of determining the well permeability profiles from well logging data using statistical relationships based upon core analysis data with a priori information incorporation is investigated in detail. The additional criteria options and ways of their application are considered. The setting and solution of a two-criterial problem of determining permeability from well logging data, care analysis data and well test data on a real West-Siberian filed is provided.
System Approach to Hydraulic Fracturing Optimization in Rosneft Oilfields
Authors: Timonov Alexey V. , Zagurenko Alexey G. , Hasanov Mars M. , Pasynkov Andrey G. , Afanasiev Igor S. 
Published: December 2007

Abstract
Nowadays hydraulic fracturing is the most successful well simulation technique, which provides a multiple increase in production and increase in effectiveness of low-permeability reservoirs development. In connection with the significant potential and, at the same time, the complexity of this type of stimulation treatment, creation of the integrated system of planning and optimization of hydraulic fracturing business-process is necessary.
The optimization of fracturing treatment design is one of the highest priority directions of integrated system. The significant number of scientific works about optimization of fracturing design is mainly dedicated to optimization of fracture parameters for creating minimum skin - factor with the defined proppant mass. At the same time, while selecting an optimum proppant mass, until now they most frequently rely only on the old proven trial-and-error method, and the diversity of specialists' opinions varies in the very broad range - from the conservative designs with the minimum volume of proppant to the aggressive designs on the possibility frontier of contemporary technology.
At the same time, the new level of technology development makes possible conducting large-volume hydraulic fracturing treatment, for successful realization of which the more careful study of the effect from different characteristics is required, including technological risks. For example, even now inside the Company there is an experience of conducting fracturing jobs up to 400 tons of proppant.
Analysis of fracturing treatments, carried out by different service companies, confirms that with a notable increase in the proppant mass absence of integral approach leads to reduction in the fracturing treatment effectiveness. First of all, this is caused by the ineffective use of a substantial part of injected proppant while conducting large-volume hydraulic fracturing.
Therefore, the need for solution of the following multiparameter problem is obvious: optimization of the mass of proppant under maximization of economic effectiveness and consideration of technological and geological risks.
The article shows the solution of this problem on the basis of integral approach using integrated technical and economic optimization of hydraulic fracturing design in Rosneft. Also the integrated system of hydraulic fracturing planning and conducting is presented. It made possible to increase considerably the effectiveness of hydraulic fracturing in the company.
A System Approach to Vankorskoye Oilfield Development Planning
Authors: Antonenko D. A. , Islamov R. A. , Stavinsky P. V. , Yatsenko V. M. 
Published: December 2007

Abstract
Rosneft Oil Company actively develops its resource base and increases oil production. Therefore, great attention is focused on the development of geologically complicated oilfields. The Vankorskoye project that has major priority for Rosneft is a striking example of such fields.
To increase efficiency of oilfields development within Rosneft Oil Company a unified design system including all stages of development – from development prospects to development monitoring – has been created. Within the system a multidiscipline workgroup has been created for designing Vankorskoye oilfield development, which is able to react actively on new information and to adapt flexibly design solutions to the new conditions. Main results of this group are design solutions considering the application of new technologies and increasing sufficiently the development efficiency.
New technologies of field prospecting and modeling are widely applied in development of the Vankorskoye oilfield that allows designing field development and decreasing risks. An application of spectrum-velocity forecasting technology at the stage of seismic data interpretation allows defining exactly reservoir properties with a small number of exploration wells. Techniques of geo-stochastic modeling reflecting heterogeneity of reservoir properties are used in geological model building.
New technologies allowing increasing oil recovery, optimizing oil production rates and decreasing field development costs are used in project design. Use of gas reinjection provides decrease of environmental damage, maintenance of reservoir pressure and increase of oil recovery. Modern techniques of well construction and operation (horizontal wells with long horizontal length and intelligent completions) significantly increase field development effectiveness.
The article below describes base elements of the Vankorskoye oilfield design system, as well as the work results and prospective of sharing experience for other Company's field development.
Re-activation of Multilayer Oil Field Development at the Late Stage of Production
Authors: Diyashev R. N. , Nurislamov N. B. , Voronovsky V. R. , Senochkin P. D. , Khussainov V. M. , Vildanov A. A. 
Published: December 2007

Abstract
Majority of the largest Russian oil fields are at the stage of depleting active resources. A problem of reactivating development of the marginally profitable old oil fields is becoming increasingly vital due to decrease in discovering of new large oil deposits. This is also witnessed by the worldwide experience of the oil industry development.
One of the major problems of the late stage development of the multilayer oil fields is a task of identifying accumulations of residual oil deposits and substantiation of geological and technical activities for the purpose of their maximal recovery.
The example of horizon D1 productive sediments in Block III of Romashkiskoe oil field Pavlovskaya area has served as a basis for implementing a set of activities to increase the effectiveness of developing a multilayer oil field at the late stage of operation, including re-interpretation of the primary geophysical data, re-appraizal of the initial oil in place, analysis of the development status, identification of areas containing residual oil reserves and justification of activities aiming to involve such reserves into the drainage process as well as analysis of all the works performed effectiveness.
The results of the works performed allowed adding recoverable oil reserves by 3.89 %, optimizing the formation and the bottomhole pressure values through water injection and product withdrawal and during the five year period allowed to additionally produce 599.1 thousand tons of oil accounting for 55.5% of the total oil production within the block during the period under consideration.
By the beginning of the re-activating activities implementation the production watercut amounted to 88.6 % with the current oil recovery factor amounting to 44.3 %.
Successful PDC/RSS Vibration Management Using Innovative Depth-of-Cut Control Technology: Panna Field, Offshore India
Authors: Jaggi Anil , Upadhaya Sunil , Chowdhury Ashabikash Roy 
Published: December 2007

Abstract
The operator has been active in Panna field for several years drilling a main horizontal and two laterals through a window milled in pre-existing 9-5/8" casing. The laterals vary in length between 800m to 1600m, depending on the carbonate reservoir's constraints. However, interbedded formations with contrasting hardness had the potential to cause stick-slip and lateral vibration.
Initially, the operator utilized RSS/MWD to geosteer the BHA within the target formation. However, previously chosen PDC bits caused severe lateral vibrations, stick slip and BHA whirl that resulted in multiple downhole tool failures. It appeared new PDC technology was required. An in-depth study revealed the BHA was exposed to severe stick-slip and lateral vibrations. There were also regular instances of BHA whirl and severe acceleration and deceleration caused by stick-slip.
To enhance overall bit/BHA stability, a new-style 8-1/2" PDC was implemented with innovative depth-of-cut control (DOCC) technology and enhanced stability features. BHA design was also reviewed and minor changes were implemented. The result was a significant reduction in stickslip, lateral vibration and BHA whirl. The new PDC/RSS set a new national Indian record for the longest 8-1/2" offshore section making 3956m of hole in a single run. The bit has since successfully drilled several multilateral drainholes in a single run proving the reliability of the new PDC design and enabling technology. The authors will present the vibration signature of a standard PDC versus the new one with DOCC. The authors will discuss proper RSS/PDC bit selection and demonstrate the benefit of DOCC/PDC on RSS when applied in high angle/horizontal wells.
Using the Technology of Intercepting To Take Precautions Against the Spread of the Worms in Intranet
Authors: Huifeng Tian , Jingxin Xu , Shubo Cai 
Published: December 2007

Abstract
With the wide application of the network the traditional virus spreading through the file has already left the leading post and the worms spreading automatically through the network suddenly become the mainstream of the virus. The worms spread all over the whole world within less than one day by utilizing hole of the operating system or application software what cause the network to slacken even paralysed. Because there are many nodes of networks in the intranet, and most users are not the professional personnel of the computer, it is no doubt important to train users their network security consciousness; but if we can find and isolate the computer which propagate the worm in time, we'll ensure the normal running of the network. The article recommended a method using the network interception technology to detect the worms according to the spread mechanism of the worms.
Drilling in High-Density and Thin-Pressure-Windows Complex Formation
Authors: Jia Guoyu , Zhang Lisheng , Duan Yongxian 
Published: December 2007

Abstract
Super-high pressure gas fields in Tarim Oilfield mostly lie in the area of Tianshan mountains. the upper cap rock of these gas fields is salt gypsum formation which is deeply imbedded, this salt gypsum formation contains not only many different pressure systems but also soft mudstone and salt-water bed with super-high pressure, 80 percent of all accidents and complex situations take place in this section. Tarim Oilfield arranges well Dina-11 in Dina structure in order to change this adverse situation; all results and achievements during drilling operation are as follows:
Drill through salt gypsum formation about more than 1,000 m, and salt-water bed with super-high pressure Drill through two low pressure formation with under balanced drilling technology Perform 16 times of blocking leakages operation with high density drilling fluid successfully Perfect well control technology for super-high pressure gas reservoir Find Dina gas field finally
Consummate the drilling technology for Shanqian structure and reduce the possibility of accidents and complex situations, quicken the speeds of exploration and development through drilling operation in well Dina-11
Study on Forming Conditions of Condensate Gas Reservoir in Deep-Seated Formation in Dongying Sag
Authors: Fenggui Sui , Guozhen Chang , Wenlin Wang 
Published: December 2007

Abstract
By the analysis of the composition, the phase and the carbon isotope characteristics of the natural gas, It reached that the natural gas reservoir of Fengshen 1 of the lower section of the forth strata of Shahejie Formation, buried underground 4300m approximately, is a secondary condensate gas reservoir, as well as an indigenously generating and accumulating gas reservoir which source rock is the dark mudstone within the salt-layer of the lower section of the forth strata of Shahejie Formation. The synchronous conglomerate fan-body and the abnormal high-pressure zone, which occur in their hanging walls of the major faults in the north of Dongying Sag, are the favorable conditions for petroleum accumulation and preservation. The thick rock gypsum deposited on the conglomerate fan-body is the best cap rock. The appropriate pressure and temperature condition determinate the formation and the preservation of the condensate gas reservoir. In Dongying period, the source rock of the lower section of the forth strata of Shahejie Formation stepped into mature stage and a great quantity of petroleum was generated and migrated laterally into the conglomerate fan-body and accumulated as a pool finally. In Quaternary Period, the petroleum in the pool was cracked into condensate gas because of the rising of pressure and temperature. In one word, the deep strata of Dongying Sag, even Jiyang Depression will be the most important domain of condensate gas reservoir exploration of Shengli Oilfield.
Studies and Application of Slag-Blocking Agent for Steam-Injection Reservoir
Authors: Pan Jingjun , Weibin Deng , Zhuofei Wang 
Published: December 2007

Abstract
With the technique of steam flooding widely used in heavy oil recovery in Xinjiang Oilfield, a noticeable steam channeling mainly caused by the heterogeneity of the reservoir and the steam overlay has been observed, which in most cases can result in a rapid increase of water cut and even in a direct production of steam in the wells. To enhance the utilization of the steam and heavy oil recovery, this work puts forward the technique of slag blocking agent for steam injection reservoir.
Based on the compositions and properties of industrial slag with silicate as the main component, the activation system, the high temperature retardant and the suspension system have been developed accordingly. The systematic investigations have been carried out on such properties of blocking agent as suspension stability, injection characteristic, initial setting time, thickening process and setting strength. The high-temperature blocking agent developed is of characteristics of better stability, easy preparation, low cost, controllable setting time and convenient in-situ operation. The field experiments were further conducted by applying the blocking agent to the selected 4 wells with observable occurrence of steam channeling in the steam injection heavy oil reservoir. The results show that the blocking agent has an excellent ability to plug the gas-channeling path, thus mitigating the steam channeling and expanding the sweep of injection steam. The good results of an increase of 3,776t oil production and a reduction of 1.5×104m3 water production have been obtained eventually.