bluuebunny/crossref_metadata_2025_split huggingface dataset:
New Formation Evaluation Parameters of Low Permeability Water Bearing Gas Reservoirs and Its Application
Authors: Guangya Zhu , Xiangui Liu , Sheng Miao , Shusheng Gao 
Published: July 2010

Abstract
The developments of gas fields and laboratory experiments present that there are great differences in the well performance and well productivity between different wells with the same reservoir petrophysics. The characters and distributions of the tight gas reservoirs are not yet well interpreted by the current formation evaluation techniques. Based on the laboratory experiments by using the rate controlled mercury injection, nuclear magnetic resonance (NMR) and physical simulation technologies, the pore microstructure features of tight gas reservoir and its influence on the formation petrophysics were analyzed. Three new formation evaluation parameters for tight gas reservoir are proposed involving mainstream throat radius, movable water saturation and gas threshold pressure gradient (GTPG). Results of the constant-rate controlled mercury injection indicated that the mainstream throat radius is one of the key controlling factors for the petrophysics of tight gas reservoir. A good correlation-ship is obtained between the permeabilities and the mainstream throat radius. Results of core flooding experiments indicated that the pore structure have eminent influence on the GTPG. The GTPG is positive correlated with initial water saturation, and negative correlated with permeability. Results indicate that the absolute open flow potential (AOF) decreases with increasing GTPG. Water-blocking would occur and reduce deliverability of gas reservoirs, when gas displacement gradient is below GTPG. The GTPG plays an important role in determining the effective drainage radius and the abandonment pressure of gas well. The movable water and irreducible water could be identified by NMR method. Results show that moving water saturation (Smw) should be an assessment indicator to the water inflow of gas well. Incorporated with petrophysics, mainstream throat radius, gas threshold pressure gradient and movable water saturation a comprehensive evaluation method has been established. Applications of this method to some of the tight gas reservoir in China get reliable consistent results.
Interfacial Mass Transfer Mechanism and Flooding Characteristics of Dead End Pore on Supercritical Carbon Dioxide
Authors: Jishun Qin , Ke Zhang , Xinglong Chen 
Published: July 2010

Abstract
Enhanced oil recovery (EOR) processes are unavoidable fact, which will be applied in oil upstream industry. It seems the miscible gas injection into oil reservoirs be one of the most effective methods in EOR approaches. Therefore, the interfacial mass transfer and dead end pore flooding of carbon dioxide miscibility flooding take part an important role in oilfield. This study is mainly conducted by reservoir flow and supercritical fluid theory. Supercritical CO2 miscible flooding mechanism and a special dead end displacement mechanism are studied in ultra-low permeability reservoir. Besides, supercritical CO2 micro-flow characteristics and mass transfer between oil and CO2 are analyzed. Using a high-speed advanced and visualization camera (5000/s) micro-simulation model, the flooding mechanism of transient dead end pore and interfacial mass transfer are both observed. The oil film migration phenomenon and the miscibility are also clarified. During the flooding, the wax in crude oil continues to deposit at pore throat to form transient dead end. Supercritical CO2 could flood the oil in dead end by the cylinder and the cylindrical flow. As existence of molecular coalesces in supercritical CO2, it has a strong ability to dissolve heavy crude oil. This study will provide a theoretical support for CO2 crude oil miscible flooding in pilot test of permeability reservoir.
Water Flood Regime Study of High Dip Reservoir with Narrow Oil Zone
Authors: Junshi Li 
Published: July 2010

Abstract
To high dip reservoir with narrow oil zone, different water flooding regime has different development effect because of the affection of several factors. Geologic ideal models with different strata dip and permeability were built in this paper. By using these models, reserve recovery degree of crest flood and bottom water flood were calculated and compared though numeric simulation. Gravity and capillary pressure, as the most important affection factors, were considered during water flooding. According to geologic characteristics of one high dip reservoir with narrow oil zone in Mongolia, a new plate of reserve recovery degree was described, from which reserve recovery degree could forecast directly.
Deep Air Drilling Application to Enhance Rate of Penetration in Extremely Hard, Abrasive and High Temperature Environment
Authors: Nas Steve , Gala Deepak , Cox Paul 
Published: July 2010

Abstract
This paper details the lessons learned in late 2007 and early 2008 whilst air drilling vertical gas wells in the Travis Peak formation of the western East Texas deep Bossier play in Amoroso Field and applying the lessons learned in the US to a deep appraisal well drilled in Northern China.
The deep Bossier represents one of the most active onshore plays in the United States. Deep Bossier wells are 14,000 ft (4,267m) to 16,000 ft (4,876m) deep and intersect shale and sandstone formations ranging between 2,000 ft (610m) and 3,000 ft (914m) thick. The Travis Peak is also known as ‘tragic peak’ during conventional drilling operations because the sandstone is hard and abrasive in nature, leading to extreme low rate of penetration (ROP). Air Drilling technology was utilized to increase the ROP through the formation at depths of 10,000 ft (3,047m) and greater. The deep exploration wells in the Daqing area of Northern China are drilled to depths of 20,000ft (6,095m) and greater in an attempt to explore the deep volcanic reservoir potential in the area.
In the US the 8-1/2-in hole size was drilled using air hammers and roller cone bits using straight air or nitrogen. Temperatures in the Travis Peal formation were reported to be above 300°F (148°C). Temperatures in Northern China were reported to be as high as 400°F (204°C) in the 12-1/4-in hole size.
The fit-for-purpose equipment needed for the air drilling sections of these wells comprised of air hammers capable of drilling in high temperatures, hammer bits with full diamond inserts, high-temperature float valves, air compressors, nitrogen production units, mist injection systems, and rotating control diverters.
The lessons learned in the US were applied to the well in China where similar results were encountered. The drive to enhance air drilling to extreme depths and high temperatures previously believed to be off limits proved to be successful in both parts of the world.
Deepwater Managed Pressure Drilling Applications
Authors: Nas Steve 
Published: July 2010

Abstract
The growing interest in deepwater exploration drilling in the Asia Pacific region has resulted in the first exploration wells being drilled in the deepwater area's of South East Asia. As these deepwater exploration wells were being drilled, the first well control issues associated with kicks and losses in the carbonate formations have also been encountered. Over 200 wells have been drilled to date in South East Asia using managed pressure drilling techniques. MPD technologies are now routinely used on floating rigs to solve the loss kick scenario's encountered in the fractured carbonates, the use of MPD equipment in deepwater (+400m) operations provides a number of additional technical challenges that are now also being addressed.
This paper provides an overview of the current MPD applications and techniques used from floating rigs. The paper then highlights the unique challenges that are associated with the implementation of managed pressure drilling in a deepwater environment. In the near future as reserves are discovered and developed in the deepwater carbonate reservoirs, solutions to the drilling challenges will have to be found to allow commercial development of these deepwater reserves in the Asia Pacific Region.
Study Damage of Rock and Evolvement of Porosity and Permeability Under Hydraulic Fracture in Ji Lin Oilfield
Authors: Zhao Wanchun , Sun Chengyan , Wang Chen , Ai Chi , Bu Zhidan 
Published: July 2010

Abstract
Firstly, in view of the mechanism of rock damage of hydraulic fracturing for oil reservoir and considering the changes of matrix porosity and micro-cracks volumes for loading on the rock, the tensor damage variable of rock damage are defined by using the changes of matrix porosity and microfracture volumes and the rock damaging deterioration model of hydraulic fracturing is obtained based on damage theory. Secondly, assuming the dynamic evolution of micro- fracture of the process of hydraulic fracturing satisfy with the Logistic fork standard model, the microfracture dynamic evolution model is established based on the damage theory and according to the conservation of energy principle of hydraulic fracturing, the relation among the strain, medium porosity and damage variable of the process of rock damage evolution is determined. Finally, the model of matrix porosity and the evolution of permeability tensor of Micro- fracture for hydraulic fracturing rock is established. Take one well in Ji-Lin oil field as object, the regularity for change of parameters of rock were obtained.
Flow Induced Corrosion of API Round Thread Connection
Authors: Hongjun Zhu , Yuanhua Lin , Dezhi Zeng , Deping Zhang , Zhi Zhang , Yongxing Sun 
Published: July 2010

Abstract
Reservoirs with high pressure and high temperature (HP/HT) situated in Northeast Sichuan of China contain high content of acidic components such as carbon dioxide, hydrogen sulfide and element sulfur. The developing conditions of these reservoirs become more and more severe for intense corrosion, which gives rise to short service time of well tube. Then serious safety accidents and environment problems would happen frequently. So investigation of corrosion mechanism and preservation technologies of well tube is very important.
Previous published papers usually focused on crevice corrosion, bimetallic corrosion and phase-change induced corrosion. However, corrosion channels are generally found in tube connecting, where the flow velocity is smaller than that in tube. This phenomenon may be explained by the flow induced corrosion. So in this paper, based on the computation fluid dynamics, governing equations of flowing fluid have been bulit. Then flow characteristics in the connection of API round thread tube were simulated. Flow field accompanied by the occurrence of vortex is changing in the tube connection, resulting in accelerated corrosion reaction, cavitation corrosion and erosion-corrosion. As time goes on, morphology of flow induced corrosion would in turn affect the flow rate, which intensifies the corrosion. Finally, some technical measures to reduce flow induced corrosion were proposed. Calculation results of this paper can provide some references to design safe well tubes and operating parameters.
Accurate Matching of Bit and Reamer Tools Delivers Optimized Drilling Performance
Authors: Barton Steve , Weeden Ryan 
Published: July 2010

Abstract
The increased use of hole opening tools remote from the drill bit has led to a critical need to understand the interaction between the drill bit and the hole opening tool itself. Problems that can result from improper matching include vibration, inability to open hole, mechanical damage to string tools or to the bit, and sub-optimal drilling performance.
This paper explores the theoretical relationship between bit and reamer and modeling the relative aggressivity and stability of both tools, building on already established indices for predicting and comparing the performance of bits. It reviews the calculations and methodology of placement and development of both the bit and reamer for optimal interaction and performance. It also considers stabilization of the hole opening tool using both concentric and eccentric devices.
The paper also reveals the development of an interactive, intranet tool. This software incorporates logic regarding the configuration of the reamer and assesses these against key characteristics of the drill bit. The tool enables the user to accurately select the drill bit that best complements the reamer that will be utilized.
A number of examples from global applications are presented. These demonstrate reduced vibration, improved hole quality and hole opening performance, superior penetration rates, and overall significantly reduced drilling costs.
Eliminating Subjectivity in History Match Evaluation Through Systematic Data Mining and Application of History Match Quality Index
Authors: Darman Nasir , Bui Thang , Moreno Juan Carlos 
Published: July 2010

Abstract
History matching is a process in which one investigates the most uncertain parameters of a reservoir model and adjusts them to achieve the best possible match with observed data. Although there exist standard processes for history matching, from manual methods to computer-assisted workflows, reservoir engineers with all levels of experience continue to find the assessment of matching quality a challenge.
This paper compares three methods of assessing the quality of a history match: expert opinion, the Sum of Square of Error (SSE), and use of a History Match Quality Index (HMQI). Expert opinion, which is based on detailed visual inspection of modeled results, provides a sufficient assessment. However, it is often subjective and depends heavily on the reviewer's experience. The widely used weighted Root Mean Square (RMS) error (frequently used as an equivalent of SSE), which measures the degree of mismatch, is often affected by data outliers. Thus, it may not be practical in special cases.
The HMQI method first assigns the match quality index a value of either 0 or 1, to classify the quality of match for each data point. The history matching quality index for each simulated parameter of a well is defined as the weighted average of all points. In addition, one can use Moving Linear Regression Analysis (MLRA) to analyze observed data. The MLRA identifies data trends and automatically removes outliers, depending on the confidence level used in the analysis. Then one uses the confidence interval obtained from MLRA to estimate the tolerance level in ranking the match quality index.
We demonstrate the application of these methods and compare their relative merits in assessing the result of history matching in a mature oil field. MLRA clearly proves its ability to identify data trends and outliers. Combining MLRA and HQMI yields a superior and more robust quantitative result, compared with the other two most common methods: expert opinion and RMS error.
Currencies and their Effect on Planning in the Oil and Gas Industry
Authors: Harden James 
Published: July 2010

Abstract
As the rise or fall of crude prices have a close correlation to the costs of oil and gas exploration and development, E&P companies should understand how the effect of a weaker or stronger US$ can affect their planning and budgeting. The purpose of this paper is not to discuss global or national spending, debt, economic growth or GDP, trade imbalances or geopolitical issues that may have caused this the dollar to weaken to rapidly (or perhaps, non-US currencies to strengthen). The purpose is, instead, to provide E&P business and strategic planners to better understand the relationship between currencies and oil prices. This understanding may assist in valuation, price forecasting, cost budgeting and capital timing requirements for the massive investments that are required to meet the world's growing energy needs.
In this paper, original analysis of historical currencies (e.g., United States dollar versus Euro) and their correlation to oil prices are examined; as well as relationships of currencies and crude price effect on public equities and the cost-of-capital implications for global and independent energy companies. Also discussed will be the relationship between oil prices and drilling contract dayrates; as well as methodology to assist in analyses of prospective dayrates.
The USD began to devalue in 2002 and the current economic cycle could last much longer than some contemporary scholars believe. It is imperative that engineers and business planners understand key economic and financial drivers when making investment decisions. The reader should gain a better understanding of how oil price and currencies affect their cost-of-equity, and how one may use macro-economic indicators when performing financial analysis and projections.
Core Testing Provides an Engineered Approach to Underbalanced Drilling in Tight Gas Reservoirs
Authors: Yu David , Nas Steve , Zheng Fenghui 
Published: July 2010

Abstract
Core analysis of tight gas reservoirs can provide an engineered approach to the selection of underbalanced pressures required to drill tight gas reservoirs and thus avoid imbibition. A small number of core samples from the Ordos tight gas basin in China were tested for imbibition and phase trapping. The analysis conducted on these cores provided a direct indication of the level of underbalanced pressure required to avoid imbibition in this tight gas reservoir.
This paper will highlight the techniques used on the cores to establish the imbibition effect and the level of underbalanced pressure required to avoid the imbibition effects. The paper will then highlight some of the additional challenges that are encountered when conducting underbalanced drilling operations in tight gas reservoirs. The paper will discuss the significant benefits of underbalanced drilling in tight gas reservoirs and highlight why underbalanced drilling technology is extremely well suited to the successful development of tight gas reservoirs. The paper will further discuss the challenges that need to be addressed when considering the development of tight gas reservoirs through the use of underbalanced drilling.
Rheology of a New Gel Used for Severe Lost Circulation Control
Authors: Nie Xunyong , Luo Pingya , Wang Pingquan , Zhang Xinmin , yang Li 
Published: July 2010

Abstract
Lost circulation is a common problem in drilling project, especially the severe loss which consumes much material and costs much time, sometimes induced wellbore collapse, drill pipe sticking, overflow, blowout and well abandon at last. Based on theory of structure liquid, supramolecular chemistry, water-solubility salt-resisting and temperature-resisting polymer, we designed and synthesized the gel, called special gel, which is used to control severe lost circulation. When dispersed in water, a reversible supramolecular structure (dynamic physical cross-linking network) developed, which rendered the dispersion some special characteristics.
This paper investigates the rheology of the gel which is accordance with pseudoplastic fluid with yield point. The gel has thixotropy, good tackifying effect and shear-thinning behavior, and visible viscoelasticity. Those rheology characteristics show the gel has the potential to plug the weak zone. The gel is hard to be dilute by formation fluids for its apparent viscosity and strong cohesive force. Its shear-thinning property can provide the gel be pumped and flow in pipes easily, and flow with high viscosity and resistance in the zone porous. And its visoelasticity make the gel has high flood efficiency to cut off the connection between the formation fluid and the drilling fluid in borehole. It will impose a higher pressure to push the gel system after the gel stay. And the gel has good Compatibility with common use lost circulation materials such as walnut shell, cement. When the loss pressure difference is too high, the gel can be used with bridge plug or cement. The gel is benefit to control severe lost circulation accompanying with water zones or overflow and loss coexist. The gel was successful to deal with severe loss in Sichuan, Changqin and Tuha oil fields in China.
New Cutter Technology for Faster Drilling in Hard/Abrasive Formations
Authors: Plemons Billy , Douglas Charles , Shen Yuelin , Zhan Guodong , Zhang Youhe 
Published: July 2010

Abstract
Drilling the hard, abrasive and interbedded Travis Peak and Cotton Valley formations in East Texas creates a difficult challenge for polycrystalline diamond compact (PDC) bits. Historically, conventional PDC cutting elements dulled quickly due to abrasive wear, impact damage and thermal fatigue. Thus, cutter technology has been the limiting factor for efficient PDC bit drilling in the East Texas Basin.
Recent technological developments have produced a new, highly abrasion resistant cutter that has increased rate of penetration (ROP) and total footage drilled in addition to producing better dull grades. Further, the sections that normally require two/three PDC bits can now be drilled in one fast PDC bit run. The new cutter technology is designed and manufactured utilizing an innovative process which delivers superior properties both in laboratory testing and field trials. The manufacturing process involves a two-step high pressure/high temperature (HPHT) technique. The first step is to make a polycrystalline diamond table (PCD) using conventional HPHT parameters. The second step is to re-attach the PCD synthetic diamond wafer on a new tungsten carbide (WC) substrate under extreme HPHT parameters. The advantages of this method compared to the conventional one-step process are as follows: The residual stress in the PCD table is reduced by the additional second processThe two-step HTHP process increases the microstructure strength of the PCD
Laboratory tests have indicated the new type of PDC cutter has increased resistance to abrasive wear and thermal fatigue by approximately 100% over standard PDC cutters while not compromising impact resistance. Extensive field tests in the East Texas Basin have documented that drilling efficiency could be improved by 20% in the hard/abrasive application. The cutters are expected to have a positive economic impact on other hard/abrasive applications worldwide.