bluuebunny/crossref_metadata_2025_split huggingface dataset:
Recent Advances and Emerging Technologies for Extended Reach Drilling
Authors: Payne M. L. , Wilton B. S. , Ramos G. G. 
Published: December 2007

ABSTRACT
Extended-Reach Drilling (ERD) is being successfully pursued by various major operators in locations world-wide. Specialized ERD equipment and operational procedures are advancing rapidly from a number of different sources. Case histories of ERD achievements and detailed analyses of specific ERD technologies are proliferating in industry literature. This paper summarizes recent advances and emerging technologies to document available systems for ERD projects and to accelerate technology transfer and development within the industry. This paper highlights recent industry ERD projects and provides specific advances in the areas of wellbore stability, drilling fluids, drilling equipment, drilling systems, and tubular design and running.
Small Diameter Packers Can Solve Big Well Control Problems
Authors: Girola G. , Cerrito E. 
Published: December 2007

ABSTRACT
Hazardous situations due to well control problems are not uncommon in exploration and production activity. Timely actions are of relevance when well conditions are time sensitive and in the presence of deteriorating situations.
In addition, precarious well conditions prevent you from taking wrong steps.
Small diameter packers and bridge plugs are often considered too weak to withstand particular environments, where pressure, temperature and mechanical stresses are present.
This paper discusses details of some utilization of inflatable bridge plugs and solid body bridge plugs, run with different techniques under limit conditions to overcome severe emergency well situations.
The Upscaling of Miscible and Immiscible Displacement Processes in Porous Media
Authors: Zhang H. R. , Sorbie K. S. 
Published: December 2007

ABSTRACT
The concept of pseudo-functions has been developed as a practical technique for representing the behaviour of small-scale multi-phase fluid mechanics and heterogeneity in coarse grid simulation models. Most of the existing methods for deriving pseudo-relative permeabilities make some specific assumptions and, for this reason, they do not apply under all conditions.
This paper explores a more general upscaling technique that may be applicable to both miscible and immiscible displacements and may be applied in arbitrary geometries and for all mobility ratios. In the new method, which is based on the approach of Stone,1 the dynamic pseudo-functions are produced from a fine grid simulation using a weighted fractional flow formulation with unit-mobility-ratio flow information. It avoids calculating the potential differences and has no limitation to flow rates. The flow rates out of the coarse grid block boundaries need to be calculated only once in producing the pseudo-relative permeabilities for "miscible" flow.
The method has been validated numerically by simulating certain immiscible and experimental miscible displacements for adverse mobility ratios within an areal quarter-five-spot porous medium on both fine and coarser two-dimensional grid meshes. Good agreement in effluent/recovery performance for the fine grid model, coarse grid model and the experiment has been obtained with a substantial saving in computing cost for the upscaled model. The new method is successful in capturing both the effects of interaction of the fluid displacement process with the small scale heterogeneity and also the numerical dispersion effects and the influence of the local boundary conditions.
Technical Challenges of the Yacheng 13–1 Pipelines Design and Construction
Authors: Wilburn J. S. , Fei Miao Yuan , Roberts P. M. 
Published: December 2007

ABSTRACT
The Yacheng 13–1 Gas Project is under development by ARCO China Inc. acting as Operator, with its partners CNOOC and KUFPEC. The field lies to the south of Hainan Island in the People's Republic of China (PRC). Gas, containing some CO2 and H2S, is due to be produced and processed through two offshore platforms in approximately 90 meters water depth.
Research on Helical Flow of Non-Newtonian Fluids in Eccentric Annuli
Authors: Cui Hai-qing , Liu Xi-Sheng 
Published: December 2007

ABSTRACT
The governing equations, the boundary and connective conditions of the helical flow of non-newtonian fluids in eccentric annuli, which are the 4th order nonlinear nonhomogeneous partial differential equations with varible coefficients expressed by the stream function and axial velocity in the bipolar coordinate system, are established theoretically and calculated numerically by using the finite difference method.
The calculation steps of the above mentioned equations are given and, being as the examples of the experimental data of the aqueous solution of CMC in the laboratory, the helical flow of the non-newtonian fluid in eccenric annuli are calculated and analysed practically. The results are as follows: There is a secondary flow, which is very important for analysing cuttings carrying capacity of drilling muds in the annuli and for preventing drill pipe from being suck, in the helical flow of the non-newtonian fluid in eccentric annuli.The flow rate of the helical flow is enhanced by the rotation of the inner cylinder of eccentric annulus.The results of comparison between the numerically calculated flow rates and the flow rates meassured in the experiments show that the governing equations and the method of the numerical calculation of the helical flow of the non-newtonian fluids in eccentric annuli in the paper are correct.
Biodegradable Invert Oil Emulsion Drilling Fluids For Offshore Operations: A Comprehensive Laboratory Evaluation and Comparison
Authors: Xiao Lihua , Piatti Cesare 
Published: December 2007

ABSTRACT
Synthetic-based mud ( SBMs ) proposed to substitute the toxic mineral oil based muds need to be fully investigated and compared on the basis of both performance and environmental acceptability. Esters, polyalphaolefins, ethers and alkyl-benzenes are the biodegradable fluids candidates to replace mineral oil and solve the critical problem of disposal of the drilled oily cuttings into the marine environment without the need of costly washing processes or transport to onshore disposal sites.
This paper describes the experimental procedures and the results of the tests and analyses performed on different pseudo-oil based mud systems: stability to contaminants, HTHP rheology, lubricity, effect on cement slurry and ecotoxicity characteristics are evaluated and compared. The study includes the investigation of the quantity of pseudo-oil retained on cuttings by the tested mud formulations.
Improved Inhibition and Rheological Properties are Observed in Amphoteric Polymer Mud System
Authors: Pinya Luo , Jian Li , Yabin Niu , Darning Zhang , Tongtai Xui 
Published: December 2007

ABSTRACT
This paper presents the design and the field application of amphoteric polymer mud system to solve the problems conventional polymer caused, when drilling high reactive shale formation. It has been studied relationship of the structural features and mechanisms of polymer molecules with the performance of polymer mud. Amphoteric polymers have been developed with cationic and anionic groups in the one polymer molecule chain to be the dual function to improve the inhibition and to maintain excellent rheology of mud. This new kind of polymer mud system has been utilized in most oilfields of China, in diverse geographic locations, formation lithologies and hostile environments such as high density, high salinity and high temperature. It has been observed in the fields that this new drilling fluid has the desired optimum shale and borehole stabilization, improved rheological properties, high rates of penetration and benefit for oil formation protection.
Very Long Reach Drilling Technology Application in North Sea
Authors: Lal Manohar , Guild G. John 
Published: December 2007

Abstract
This paper discusses the design and application of the drilling and wellbore stability technology for an extended reach well drilled in the UK sector of the North Sea Central Graben Basin. The use of this technology can provide reservoir and development planners with an alternative means to economically and efficiently develop accumulations which are situated beyond conventional reach of drilling platforms. Very long reach drilling can enable developers to either defer or eliminate the capital spending associated with additional platforms and facilities or subsea development of satellite accumulations.
The paper addresses several areas that include mud weight and mud system, rock mechanics aspects impacting well-bore stability, well path design, drill string, casing and cementing considerations. It gives a detailed discussion of how the safe operating window for the mud weight was predicted from stability analysis and used to successfully drill the South Everest Extended Reach well (SEER T12) to TD. The paper also describes the rock mechanics data, in situ stress and pore pressure analysis, and operational practices trying to maintain the desired equivalent mud weight within the safe operating range.
Development Adjustment of Heterogeneous Sandstone Reservoir at Late Period of High Water Cut Stage
Authors: Heng Liu , Xinde Wan 
Published: December 2007

ABSTRACT
Severe heterogeneity of continental sandstone reservoir has set great difficulty for understanding and smoothly developing oil field. But can we make effective adjustment at late period of high water cut stage making use of this characteristics? Daqing oil field has made useful attempt, including developing new technologies to deepenly tap the two sides potential of thin, poor and thick reservoirs through fine reservoir description; conducting development adjustment in old area by taking advantage of various differences in oil field development caused by heterogeneity to realize oil production replacement and maintain oil production stabilization at the level of relatively high annual oil production; fluid production and water cut increase rate are also effectively controlled, opening up a new way of niaintaining oil production at late period of high water cut stage, and obtaining considerable economic benefits. Practice proves that this set of methods are novel in thought and feasible economically, and can promote the development of reservoir description and developing technology. So systematic introduction is presented here just for reference for the same type of oil fields.
Modeling Transient Wellbore Behavior in Horizontal Wells
Authors: Su H- J. , Lee S. H. 
Published: December 2007

ABSTRACT
For long horizontal wells, the pressure drop along the well can exceed the drawndown between the wellbore and the reservoir. Therefore, it is very important to calculate the wellbore pressure profile with accuracy when determining the productivities of horizontal wells.
A comprehensive wellbore model, based on a transient, two-fluid approach, has been implemented in a general purpose reservoir simulator. The model can handle black oil, miscible, thermal, and compositional cases. The wellbore is represented by one dimensional finite-difference grid-blocks which are simultaneously solved with reservoir grid-blocks. A mechanistic model of multiple-phase fluid flow is employed to calculate flow regime identification, interfacial drag, and friction losses between the tubing wall and fluids. Phase changes and heat transfer inside the wellbore are also rigorously modeled.
Several horizontal well examples including the seventh SPE comparative project are studied. It is found that the production profile along the well can be very different between the cases with and without wellbore hydraulics. However, for most cases, the wellbore hydraulics impact on the ultimate oil recovery is minor unless the reservoir is poorly communicated within itself. In addition, we use the transient wellbore model to study the performance of a horizontal steam injector and the transient wellbore behavior of a shut-in well.
The use of the comprehensive wellbore model can be very time-consuming from the CPU standpoint, especially for extremely transient cases. For CPU time efficiency, we also have implemented a simplified approach to model the wellbore hydraulics, based on a steady state correlation. The phase changes and heat transfer inside the wellbore are neglected in the simplified approach. The results from this simplified approach are compared with those from the more rigorous comprehensive wellbore model.
Enhanced Geostatistical Mapping of Reservoir Fluids
Authors: Pérez G. , Chopra A. K. , Severson C. D. 
Published: December 2007

Abstract
Monitoring fluid movement is important for selecting infill locations and completion intervals and optimizing production operations in reservoirs producing under waterflood and gravity drainage mechanisms. Estimation of the fluid contacts in the interwell regions can be difficult due to complex interactions between fluid movement and reservoir heterogeneities. Previously, we developed a systematic geostatistical fluid mapping methodology that integrates multiple sources of data and accounts for the spatial correlation and uncertainty due to the sparcity of the data.1 We found that this methodology is more efficient and accurate than the conventional mapping approach. This paper describes several enhancements incorporated into the geostatistical methodology and evaluates their advantages.
The major sources of data used in the geostatistical methodology are the surveillance and shale databases. The surveillance data provide the locations of fluids (oil, gas and water) intervals at the wells based on logs. The shale data provide the locations of shales intervals at the wells based on cores and logs. The first step in the methodology is to transform the surveillance and shale data into indicators. Then, the methodology uses indicator variograms to evaluate the spatial correlation of the data. The last step generates multiple equi-probable three-dimensional fluid and shale descriptions using a conditional simulation technique that honors the well data and variograms.
The enhancements introduced into the geostatistical methodology account for more information about the data and quantify the quality of the surveillance data. The stratigraphic coordinates and vertical proportion curves account for variations in the reservoir structure and major trends in the data, respectively. The indicator variables for fluid movement at different times and shales in different zones account for the different correlations. The quality variables account for the degree of confidence engineers assign to the log interpretations. Cross-validation of the enhanced methodology consisted of the.estimation of fluid column thicknesses at infill locations and visualization of three-dimensional distributions of oil and gas in a gravity drainage area of Prudhoe Bay. The results of the methodology are in excellent agreement with actual data.
The First Experimental Hydraulic Energy-Storing Workover Rig XXJ 300/600
Authors: Xin-yi Gu , Yun-an Wan , Wei Pan 
Published: December 2007

ABSTRACT
The hydraulic energy-storing workover rig is a new type of rig invented by the authors of this paper. The first experimental rig has passed through field test (see Fig. 1). This rig differs from other types of workover rigs not only in appearance but also in working principle.
There is an energy-storing system, so some energy issued from motors or from running down pipestring can be stored and used later when needed. This new invention has obtained a lot of advantages such as energy saving, safety, less noisy, possibility of using hydraulic tubing tongs without another hydraulic system, etc.
Analysis and Design of Articulated Downhole Motor Assembly for Short Radius Horizontal Drilling
Authors: Yinao Su , Yundun Chen , Junping Zhao , Hai Zhang 
Published: December 2007

ABSTRACT
This paper offers a study of a new model of articulated downhole motor assembly for short radius horizontal drilling. Theoretical analysis of this model and relationships among acting forces, deformations, structure, borehole geometry and operating parameters are given. Design principles of the assembly configuration and main conclusions are also presented.
The Application of Acoustic Full Waveform Logging in Petroleum Engineering
Authors: Yan Shuwen , Chang Guizhao , Zhang Yongmin , Qiao Wenxiao , Du Guangsheng 
Published: December 2007

ABSTRACT
This article briefly introduces the application and processing of acoustic full waveform data and dipole shear imager (DSI) data. The emphasis is on the applications of compressional waves, shear waves and Stoneley waves in the calculation of mechanical parameters of rock. The actual results is given through the analysis of in-situ applications.
Fracturing Fluid Leakoff and Net Pressure Behavior in Frac&pack Stimulation
Authors: Fan Yong , Economides Michael J. 
Published: December 2007

ABSTRACT
A rigorous model that describes the transient flow of a polymer solution displacing a reservoir fluid was developed as a means to account for leakoff phenomena and net pressure during frαc&pαck treatments. An exact solution with a moving interface problem was derived in terms of the pressure profiles from the fracture face into the reservoir, in turn determining the fluid leakoff rate. The results show that the leakoff rate is dependent on the fracture net pressure, fluid and rock properties and injection conditions. The concept of a constant bulk property such as the leakoff coefficient is no longer necessary (or physically meaningful) in high-permeability reservoir stimulation. The developed leakoff model has been incorporated into a fracture propagation model to predict fracture dimensions, net pressure and the interactions between leakoff and created fracture during the propagation, packing stage and fracture closing. The variation of the slope behavior of the net pressure with time at a constant injection rate suggests a new method to diagnose fracture tip screenout.
Reservoir Description From Static and Well-Test Data Using Efficient Gradient Methods
Authors: Chu L. , Reynolds A. C. , Oliver D. S. 
Published: December 2007

ABSTRACT
Recently, we have shown that inverse problem theory can be applied to generate realizations of a two-dimensional permeability field conditioned to the variogram and pressure data. In this work, we extend the approach to the generation of well skin factors and two-dimensional porosity and permeability fields that are conditioned to porosity and permeability variograms and multi well pressure data. Multiwell production data as well as multiwell interference test data are considered. We show that in certain instances the incorporation of "hard" porosity and permeability data reduces the uncertainy in our estimates of rock properties and well skin factors.
X-Ray Imaging of Waterflood Fluid Saturations in Heterogeneous Rock Slabs
Authors: Huang Y. , Ringrose P. S. , Sorbie K. S. 
Published: December 2007

Abstract
X-ray computerised tomography (CT) has been increasingly applied in the study of rock properties and the in-situ monitoring of fluid displacements. A series of oil-water drainage-imbibition floods in laminated rock slabs have been performed in this laboratory. X-ray CT imaging techniques were used to evaluate the rock characterisation and to monitor the fluid saturation processes.
This paper describes significant technical advances in X-ray measurement of fluid saturations in very heterogeneous rock slabs. Approaches to minimising the beam hardening effect and suppressing high-frequency artefacts are also described. A number of typical experimental results indicate that our improved CT techniques can be used to accurately evaluate the rock heterogeneity and its effects on fluid displacements. These include the distribution of porosity and permeability in a laminated aeolian sandstone, the distributions of irreducible water and remaining oil saturation, as well as oil recovery. CT measurements were checked and calibrated against probe permeameter and fluid mass balance measurements and excellent agreements has been obtained.
At capillary-dominated conditions (low flow rate and unit ratio of water to oil viscosity), the average remaining oil saturation is around 35–40 % of OOIP. For flow across lamina, about 30–55% of the original oil was trapped in the upstream regions of low permeability layers due to the interaction of capillary forces with the lamination. For flow along lamina, the capillary trapping is reduced but flow bypassing results in similar levels of oil retention. The distributions of remaining oil saturation and oil recovery across lamination shows clear variations related to the local permeability and the initial oil saturation. By incorporating the detailed petrophysical analyses into a simulation model, an excellent match of experiments with numerical simulation was obtained both for cross-lamina and along-lamina flows.
These findings have important implications for the determination of field-wide residual oil saturation from core plug measurements.
Completions and Stimulations for Coalbed Methane Wells
Authors: Palmer Ian , Vaziri Hans , Khodaverdian Mohamad , McLennan John , Prasad K. V. K. , Edwards Paul , Brackin Courtney , Kutas Mike , Fincher Rhon 
Published: December 2007

Abstract
Amoco is producing coalbed methane from several hundred wells in both San Juan and Warrior basins. These wells were completed/stimulated in one of two ways: (1) openhole cavity completions, (2) hydraulic fracture stimulations through perforations in casing. Cavity operations are described, and new data from several cavity completions is presented and analyzed. The latest geomechanics modeling of the formation of cavities in coalbeds is presented. The model allows the growth of a cavity as tensile failure occurs, and computes increases in permeability in a stress-relief zone that extends tens of feet from the well. Critical parameters are given for the success of cavity completions. A pulse interference analysis is discussed: as well as interwell permeability, this can provide information on stress-dependent permeability. Finally, some wells which were originally cavitated did not perform up to expectation, and have been recavitated with remarkable success – these are also examined.
Amoco has tried several different kinds of hydraulic fracturing treatments. Results of comparisons between foam fracture, slick water fracture, and gel fracture treatments are presented. Statistical comparisons are given for regions outside of the fairway zone in the San Juan Basin. In the Warrior Basin, water fracture treatments with and without sand have been compared. Lastly, foamed water cleanouts, without sand, have been deployed, and their success is reviewed.