bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Methodology on Reservoir Modeling in the Fracture-Cavity Carbonate Rock of Tahe Oilfield
Authors: Liu Xueli , Yang Jian , Li Zongyu , Wang Yang 
Published: December 2007

Abstract
Tahe, one of the largest scale oilfields which are discovered in western China recently, in which Ordovician carbonate as the main storage, characterized with deeply embedding and various storage type, mainly are cavities and fractures. It is difficult to describe as its serious heterogeneity and there is rare technical reference regarding the reservoir modeling methodology.
Commonly, the geology modeling is based on well logging and seismic data, and the stochastic method is reasonable applied. However, Tahe oilfield has very limited seismic data and poor well logging interpretations, especially for the fracture-cavern section. Furthermore, as it is controlled by paleukarst, the stochastic geological method, which is widely used in the ordinary sedimentary, is unacceptable to Tahe. The volumetric reserves calculation, which is suitable to sandstone but is not applicable to the fracture-cavity reservoir either, as it can not be proved in the severe anisotropy fracture-cavity carbonate formation. Furthermore, the concept of porosity and saturation is less meaningful in this kind of reserves. As a result, there is no applicable modeling method to describe the geological characters of the Tahe carbonate reservoir.
A new methodology which is characterized by the fracture-cavity volume is presented in this paper. Accordingly, a new reservoir modeling and a new reserve calculation is built up. Mainly from geology, combined with static and dynamic data, a quantified 3-D reservoir model of Ordovician reservoir is formed, and this modeling methodology is proved practically by the results of history match from the streamline numerical simulation. The result will technically support the exploitation of Tahe oilfield.
The Study and Application of Hydraulic Fracturing and Acidizing in Exploration Wells in China
Authors: Lei Qun , Ding Yunhong , Jiang Tingxue , Xu Yun , Song Shemin , Liu Yanxue , Liu Yincang , Cai Bo , Duan Yaoyao 
Published: December 2007

Abstract
The characteristics of exploration zones in China in recent years are summarized as: 1) Special lithology such as volcano and clay-carbonate, etc. 2) low porosity and ultra-low permeability; 3) Complex storage types and fluid flow mechanics as a result of natural fractures distributed stochastically; 4) Special in-situ stress and loss characteristics; 5) complex rock mechanics and elastic-plastic traits; 6) Undetermined fracture height growth; 7) complex stress sensitivity. Therefore, a systematic technologies are put forward in the paper, the highlights are: 1) Systematic formation fine evaluation which contains Nuclear Magnetic Resonance, Constant Rate Mercury Injection and so on; 2) Low damage fracturing fluids such as super grade Guar fracturing fluid and its combination with liquid nitrogen, low cost VES(less than 300 RMB below 90 ° C), low polymer concentration fracturing fluid and linear gel, and variable viscosity is utilized in different treatment stage; 3) Different type and diameter proppants are used in one treatment job, and the combined ratio is optimized; 4) A new method of multiple stage optimization is put forward to ensure not only the success of stimulation treatment but also the maximal post-treatment performance; 5) Counter measures are applied systematically such as two combinations of pumping rate and viscosity to control loss and multiple fractures, fracture height control, systematic quality control and post-treatment management, etc. What's more, above technologies have been put in to field applications in more than 39 wells in the year of 2005, and the result is satisfied with the newly increased oil reserves being greater than 1×108 t, gas reserves greater than 800 × 108 m3. Consequently, it has a great significance in China's main exploration zones, in the mean time, it also has a great benefit of economy and hydraulic fracturing and acidizing themselves.
The Reservoir Simulation Research and Extending Application About Cyclic Water Injection
Authors: Yaozhong Yang , Tao Dai , Chengfeng Wang 
Published: December 2007

Abstract
In this paper, reservoir simulation model is built so that the geological characteristics of West region in Gudao oilfield, which has entered into very high watercut development period, are described finely. Then, the production history of about 20 years was matched. Base on the exact geological model built through history match, the remaining oil distribution and cyclic waterflooding mechanism was studied systematically. The research achievements can be taken as reference for the similar reservoirs which have entered into high or very high watercut development period and have improved development effects of different types of reservoirs after field application.
Adoption of RSS Speeds up Extended Reach Drilling in Mumbai High
Authors: Kali A. T. , Mishra A. K. , Sinha S. C. , Gupta N. J. 
Published: December 2007

Abstract
To increase productivity and profitability from Mumbai High field drilling of ERD wells had to be implemented. Using ERD techniques, new infill wells had to be drilled, which were otherwise not cost effective. Uses of Hi-tech tools were considered necessary to drain oil from distant subsurface locations, thus eliminating prerequisite of constructing new platforms for such wells. Further, these types of wells were presumed to serve significantly to achieve new enhanced production from the reservoir.
Experience of drilling an ERD well in 1995 with the available drilling tools and conventional mud system conveyed that these wells could not be drilled to longer departures of 2 Kms from platform to L-III reservoir level owing to onset of complications like formation collapse and stuck pipes before reaching the target. Even casing could not reach bottom due to the swelling in shales which were exposed for a prolonged duration. Feasible departures from platform were of the order of 1500 to 1600m only. However to enhance production in limited time, the need was to drill wells from an existing wellhead platform to reach a substantially far subsurface location in the reservoir. A tool was needed which can drill a well up to 2 Kms departure at landing point so that oil can be drained from a subsurface location as far as 3.5 Kms, keeping 1.5 Kms as drain hole. To overcome previous constraints in drilling, Rotary Steerable System (RSS) was adopted in the year 2003 and its use has reduced the drilling time of extended reach (ERD) wells noticeably as compared to previous wells. Targets from platform to entry point at producing reservoir L-III has been increased to 2.2 Km and total well length to 3.5 km. 12 ¼" section of 1597m inclined at 75° was drilled successfully in one week with the Rotary Steerable System and Glycol mud as drilling fluid. Drilling time has been additionally reduced by 3.25 days with oil Base mud used with Rotary Steerable System. The average number of drilling days, which were 95.87 in 95–96, has been reduced to 45 days today. The system have been found indispensable
for drilling ERD horizontal wells of lower layers of L-III in Mumbai High and it's adoption in 8½" hole size have opened the possibility of drilling a well with a departure of more than 5 Kms.
Optimizing Horizontal-Well Steam-Stimulation Strategy for Heavy-Oil Development
Authors: Luo Shanqiang , Baker Andy 
Published: December 2007

Abstract
The world still contains tremendous heavy oil resources. Ever-increasing energy demand requires more attention to be paid to harvesting all hydrocarbon resources, including heavy oil. The use of thermal processes has proven by far the most effective approach in producing heavy oil.
This paper proposes a practical steam stimulation strategy for heavy oil development using horizontal wells. In the proposed process, steam is cyclically injected through a horizontal well pattern to heat near wellbore reservoirs, and after a period of cyclic steam stimulation, one of the pattern wells is converted to a steamflooding well and the other pattern well is converted to a production well.
Through 3D reservoir simulation, this paper compares production performance of the proposed strategy with conventional cyclic steam stimulation (CSS), steamflooding (SF), and steam-assisted gravity drainage (SAGD).
A sensitivity analysis is also conducted to study the effect of oil viscosity and reservoir permeability on horizontal well production performance under different production strategies.
A Correlation Approach for Prediction of Crude Oil PVT Properties
Authors: Hemmati M. N. , Kharrat R. 
Published: December 2007

Abstract
Up until now, no specific correlation has been developed to estimate PVT properties of Iranian crude oils, nor do existing correlations estimate these properties with efficient accuracy. In this paper, however, an attempt has been made to develop a number of correlations for Iranian crude oils, using about three hundred PVT reports. These correlations were developed for bubble point pressure, solution gas oil ratio (Rs), and oil formation volume factor (OFVF) at bubble point pressure. The data used to develop the correlations cover a wide range of reservoirs with oil gravity of 18.8 to 48.34 API°.
It was found that the new correlations estimate PVT properties of Iranian crude oils much better than the published ones. The absolute average deviation for Pb, Bo, and Rs are 3.67%, 1.08%, and 4.07% respectively.
The results show that PVT correlations can be placed in the following order with respect to their accuracy for Iranian crude oils:
– Pb: Hemmati, Al-Marhoun3, Standing1, Hanafy4, Dindoruk5. – OFVF: Hemmati, Petrosky7, Standing1, Glaso2, Dokla6, Al-Marhoun3, Hanafy4. – Rs: Hemmati, Standing1, Al-Marhoun3, Dindorak5, Glaso2, Petrosky7.
Identifying Infill Locations and Underperformer Wells in Mature Fields Using Monthly Production Rate Data, Carthage Field, Cotton Valley Formation, Texas
Authors: Jalali J. , Mohaghegh S. D. , Gaskari R. 
Published: December 2007

Abstract
Recent increase in global demand for energy and the consequent high prices have prompted a need for improving the recovery from mature reservoirs. Identifying sweet spots in these fields for in-fill drilling and ranking the infill locations based on their potential productivity as well as underperformer wells as candidates for remedial operations are important for improving the economics of mature fields.
One of the most important issues that make analysis of mature fields quite challenging is lack of data. Production rate data is about the only data that can be easily accessed for most of the mature fields. The most accessible production data usually does not include flowing bottom-hole or well head pressure data. Lack of pressure data seriously challenges the use of conventional production data analysis techniques for most of the mature fields. The motivation behind development of the techniques that are presented in this study is to demonstrate that much can be done with only monthly production rate data in order to help the revitalization of mature fields.
Methods currently used for production data analysis are decline curve analysis, type curve matching, and history matching using numerical reservoir simulators. Each one of these methods has its strengths and weaknesses. They include significant amount of subjectivity when they are used individually in the context of production data analysis.
In this paper, intelligent systems are used in order to iteratively integrate the abovementioned techniques into one comprehensive methodology for identification of infill drilling locations as well as underperformer wells that would be the prime candidates for restimulation and/or workovers. Application of this technique to a large number of wells in the Carthage field, Cotton Valley formation is presented.
Multistage Fracturing System: Improving Operational Efficiency and Production
Authors: Seale R. , Donaldson J. , Athans J. 
Published: December 2007

Abstract
Over the last several years there have been many technical developments in horizontal completion methods. These developments have been designed to better stimulate the entire horizontal interval. For cased and cemented applications, composite plugs have provided the ability to segment the horizontal wellbore into sections and divert the stimulation as designed. However, the process of setting a plug on coiled tubing (CT), perforating, stimulating and then repeating the process for the required number of stages to optimize production and then running back in with CT to remove the plugs can take weeks to complete. For open hole applications, horizontal stimulations have relied solely on bullheading in stages in an attempt to generate multiple fractures. This has proven in many cases to only stimulate certain sections of the wellbore leaving much of the horizontal section unstimulated.
A new completion system has been deployed in over 300 wellbores in various producing formations, such as sandstone, limestone, shale, dolomite and coal. This system uses a series of mechanical open hole packers deployed on the production liner with fracturing or stimulation ports located between the packers that allow for stimulation in each desired interval. Without the requirement of cementing the liner in place, all the problematic issues associated with cementing are eliminated. Additionally, the use of mechanical packers provides positive mechanical diversion at high differential fracturing pressures. The system has also been designed, so all of the fracturing or stimulation treatments along the horizontal wellbore can be pumped in one continuous operation, thus minimizing the associated risks and optimizing the efficiencies of both the personnel and equipment needed to perform the work. This paper will detail the operational efficiencies and reliability of this novel completion system, as well as analyze the cost benefits and production increases that have been noted.
An Intelligent Portfolio-Management Approach to Gas Storage Field Deliverability Maintenance and Enhancement: Part One—Database Development and Model Building
Authors: Malik Kazim , Mohagegh Shahab , Gaskari Razi 
Published: December 2007

Abstract
The main goal of this paper is to modify and apply the state-of-the-art intelligent, optimum portfolio management to the gas storage field in order to optimize the return on investment associated with well remedial operations. It continues the development of a methodology for candidate selection and stimulation design and optimization using Artificial Intelligence techniques.
The data of an actual gas storage field was used to test the results. The project data include Well-bore, Completion, Perforation, Stimulation, Well-test and Reservoir Data. To make candidate selection for gas storage fields operators predict the effectiveness of the stimulation commonly using three parameters. One in Peak Day rate second is Absolute open flow and third is change in skin provided permeability values in the field don't vary much. The software developed in parallel with this selection methodology includes an easy to use interface that allows the user to edit the data for a gas storage field, perform well-test analysis and use neural networks in association with Genetic optimization tool. The software ranks the well according to maximum change in skin value and recommends the best stimulation slurry based on the weitage given to the skin and cost of stimulation. A decision to select the ranked wells for re-stimulate can be made accordingly.
Identification and Analysis of Fields for Waterflood-Enhanced Recovery Efforts
Authors: Hall Rod , Ross Dwight , Stevens Greg , Muehlberger Steve 
Published: December 2007

Abstract
Changing economic conditions allow for a new examination of mature and abandoned fields to identify oil that is now economically recoverable (reserves). In mature oil producing basins there are many inactive or limited stripper production fields, all potential waterflood candidates.
We present a methodology of identifying such fields, quantifying the incremental waterflood production, and creating a field development plan. Production forecasts are generated in a timely and cost effective manner for development scenarios with Time Dynamic Volumetric Balancing methods.
The field reviewed and used as an example is the Belcherville Field. It is a Caddo Conglomerate, located in Montague County, Texas, discovered in 1946. Developed in the 1950's, 9 wells produced 3 mmbo of primary production before being abandoned in 1967. Production was from the channel deposits of the Caddo formation that are draped over a gentle anticline. A comparative study of 7 other fields in the same trend indicates waterflooding can recover and additional 84% of primary recoverable oil.
Optimizing Drilling Operations in the Arkoma Basin: Building on Success
Authors: Romo Louis A. , Bert David R. , Richard Cliff , Kuwertz Luke , Koederitz William L. , Card Kirk , Barton Steve 
Published: December 2007

Abstract
The Red Oak Field is located in the Arkoma Basin in Southeastern Oklahoma. The Field recently exceeded peak production levels in what was previously deemed a fully developed reservoir, through an ongoing successful infill drilling program based on the use of three-dimensional (3-D) seismic. Moreover, the redevelopment program has surpassed the 100 well mark and has delivered some high rate gas wells.
The field may be characterized by its dry gas and multiple pay horizons in what has long been known to be "crookedhole country". In situ compressive strengths range from 10,000-psia through the Pennsylvanian to 55,000-psia through the Ordovician.
Much work has been done in the past to optimize air drilling operations for shallow wells; however, as deeper horizons are exploited new technologies have been implemented in order to deliver continuous improvement.
Drilling improvements in recent years have included the introduction of a state-of-the-art drilling rig, further optimization of air drilling operations and the introduction of Polycrystalline Diamond Compact (PDC) bits. A down-hole vibration mitigation effort was also initiated which yielded improved bit runs and the identification of micro-tortuosity and weight transfer issues. Vibration mitigation resulted in the redesign of bottom hole assemblies (BHA) and the optimization of bent-housing steerable-motor angle settings.
Rig rates have increased over time, along with the need for designer wells. Rotary Steerable Systems (RSS) were therefore implemented to address these issues. Initial attempts indicated that RSS were not able to overcome the formation tendencies in 3-D space. A detailed investigation resulted in the hypothesis whereby speeding up the RSS with a motor would provide enough side force with a push-the-bit system to overcome formation tendencies. Real-time Mechanical Specific Energy (MSE) measurements were used in conjunction with the implementation of a Powered Rotary Steerable Systems (PRSS) and revealed the fact that the full benefit of the RSS was not consistently realized (mostly due to the extreme nature of the drilling environment). As such, prototype extended-gauge PDC bits were designed in order to further reduce down-hole vibration, improve well bore quality and bit performance. The result has been sustained top quartile performance, a state drilling record and the continued growth of a mature field.
Permeability Damage Due to Water Injection Containing Oil Droplet and Solid Particles at Residual Oil Saturation.
Authors: Ali Mohammad A. J. , Currie Peter K. , Salman Mohammad J. 
Published: December 2007

Abstract
Re-injection of produced water is of increasing importance as water cuts continue to increase worldwide. It provides an environmentally acceptable solution to the disposal of produced water, and contributes to pressure maintenance when injection takes place into the reservoir itself. Injection can take place under matrix injection or fracturing conditions. In both cases, the performance of the injection well and the distribution of the injected water are strongly influenced by the build-up of formation impairment around the wellbore or the fracture face. Solid particles and small oil droplets dispersed in the injection water are deposited in the formation by a process of filtration, and therefore will cause this impairment.
As part of a study on formation damage, different concentrations of oil droplets and hematite particles suspended in water were injected into sandstone core samples. A particle analyzer was used to measures the inlet and outlet concentrations of each particle type, concentration and size. The analysis confirms the high impact of oil concentration with the presence of solid particle on permeability damage. Preparation of oily-water emulsion is very challenging to achieve without chemical agents or mechanical devices. The presence of solid particles present in oily-water emulsion act as emulsion stability agents. Hematite particles being oil-wet, improved emulsion stability. Permeability impairment due to oily-water alone at residual oil formation is insignificant, and the size of oil droplets does not play a big role in injecivtivity decline. However, oily-water containing solid particles causes severe permeability damage. Furthermore, if the deposition of solids increases to a critical concentration, it could create a high differential pressure mobilizing some of the trapped residual oil.
Underbalanced Drilling Successfully Implemented on First Dual Lateral Well in Libya
Authors: Safar Hussein , Azhary Sadek , Hijazi Ahmad , Qutob Hani , Chopty James , Pham Chau 
Published: December 2007

Abstract
The B24 well in the Fidaa Field was the first dual lateral underbalanced horizontal well drilled in Libya and the second well of Zueitina Oil Company's (ZOC) underbalanced drilling campaign.
The targeted reservoir "Facha" is partly depleted after 23 years of production to a 7.2 ppg equivalent mud weight. Nitrified diesel, a two-phase drilling fluid, was used to drill the reservoir section of the B24 underbalanced to avoid circulation losses and formation damage. Real time LWD was crucial for geosteering the well path in a complex reservoir structure and real time annular pressure measurement was also necessary to ensure the underbalanced condition was maintained throughout the entire UBD drilling phase.
Two 6" horizontal drains were drilled successfully with 2053" and 1517" drain lengths. Integrated efforts of ZOC and service companies of various disciplines during planning and operation stages of the well led to the success of the project. No QHSE incidents were reported and the productivity of the well was enhanced significantly.
The B24 well's production alone contributes to over 30% of the total Fidaa field production.