bluuebunny/crossref_metadata_2025_split huggingface dataset:
Oriented Fracturing: A New Technique to Hydraulically Fracture Openhole Horizontal Well
Authors: Abass H. H. , Soliman M. Y. , Tahini A. M. , Surjaatmadja Jim , Meadows D. L. , Sierra Leopoldo 
Published: October 2009

Abstract
Successful fracturing treatment necessitates expensive completion assembly that provides some form of isolation to perform controlled fracturing treatments. Currently isolation is performed mechanically which dictates that isolated interval is very short. This in turn may require that the well is cased, cemented and perforated. This would increase the cost of completion significantly. Another option is to focus the fracturing energy via the use of hydrajetting. In this paper we present another approach that provides a high degree of control on where the transverse fractures will initiate and propagate.
The various existing techniques for creating multiple hydraulic fractures along an openhole horizontal well are briefly summarized. Laboratory experiments shedding light on some of these techniques will be first presented. The new technique to precisely place a hydraulic fracture in an openhole horizontal well drilled in any direction relative to the in-situ stress field is presented. The new technique is based on rock mechanics understanding of an openhole horizontal well under a given in-situ stress field; thus it accounts for the near wellbore stress field to ensure creating a planar hydraulic fracture. Additionally, the new technique does not require costly mechanical isolation to place a hydraulic fracture. Basically, the new technique aims to bypass the near wellbore stress field such that the fracture can be conveniently initiated independently of the stress direction.
This new approach is validated using laboratory experiments which will be discussed in details. The experiments were performed on simulated wells casted in rock samples with dimensions of 6"× 6"×10". The samples were triaxially loaded simulating various arrangements of a given wellbore relative to the in-situ stress field. Then, the simulated wells were hydraulically fractured using water based gel. Fracturing pressure versus time was recorded and analyzed.
The experiments were very successful in proving the new concept to fracture openhole horizontal wells. The developed technique is fairly easy to implement and the impact of precise placement of a hydraulic fracture across an openhole horizontal well is illustrated.
New Technique to Determine Biot Coefficient for Stress Sensitive Dual Porosity Reservoirs
Authors: Abass H. H. , Tahini A. M. , Abousleiman Y. N. , Khan Mirajuddin 
Published: October 2009

Abstract
Poroelasticity plays a vital role in many applications of rock mechanics in petroleum engineering. To model dual porosity stress sensitive reservoirs such as tight gas, it is necessary to quantify the stress-dependant hydraulic conductivities of their porous components, the matrix and natural fractures. The role of effective stress concept near the wellbore is more pronounced as the reservoir pressure declines rather rapidly approaching the bottom hole flowing pressure. The porous media changes when reservoir pressure is altered and therefore the elastic coefficient (α) becomes a function of reservoir pressure for both components; matrix and fractures.
Rock samples from tight formation were tested to determine the stress-dependant matrix permeability. Various combinations of net effective stresses were applied and the corresponding permeabilities were measured at each stress level. Applying the definition of effective stress with an iterative assumption of Biot's coefficient enabled the determination of (α) as a function of pressure.
Additionally, the Biot coefficient was determined for a natural fracture. A tensile fracture was simulated by splitting a whole core following a Brazilian test procedure. The stress dependent permeability was evaluated under varied effective stresses simulating a reservoir depletion scenario. The concept of effective stress within the natural fracture was totally different than that of rock matrix; therefore, the effective stress function for both matrix and natural fractures were evaluated and representative functions for both media were obtained. These stress-dependent permeability functions can then be used in any rock mechanics application in petroleum engineering. The developed experimental procedure is fairly simple and is discussed in details, and selective relavant applications are presented.
The new technique for determining the Biot coefficient is based on the application it is being used for; the effect of effective stress on matrix and natural fracture permeabilities. This paper shows that two poroelastic coefficients, and not one, should be used in any dual porosity system to obtain reasonable prediction of reservoir performance. Varying the coefficient as a function of pore pressure allowed for determining a pressure dependant function for a given porous medium.
A New Performance Award System for Petroleum Engineering Students - Development and Implementation
Authors: Williams John M. 
Published: October 2009

Abstract
A system was developed to give public recognition to high-performing students and encourage other students to strive towards better performance. Two categories of award were established, one for the best performance, and one for the most-improved performance, to add incentive to students who did not think they were in the top echelon of performers. Much effort was put into developing award rules which would ensure students were taking effectively full technical course loads, and would cover numerous complications, such as change of student level between semesters, students switching majors, uneven workload between semesters, possible faculty bias in faculty voting, and tie-break rules. Different types of award gift were evaluated in the light of local culture and traditions, and a non-financial award was considered to be most appropriate.
Many universities are introducing or expanding Petroleum Engineering (PE) programs due to the serious worldwide shortage of petroleum engineers. These applied engineering programs probably involve the most significant progression from basic science, and thus can be very challenging to many students. Presentation of rewards for successfully making the transition motivates students, and provides an important component in department activities each semester.
Awards have now been presented since the academic year 2006-7, with significant interest and competition for awards being demonstrated. Only small rules clarifications have been required since. A survey of students and past graduates has given positive feedback to the award program, though a number of possible improvements have been identified. Other programs at the Petroleum Institute have adopted the same or similar award system.
This issue has not been addressed in an SPE publication previously. The paper provides full details of the student selection procedures which could be adopted by other universities.
Taking Real Options into the Real World: Asset Valuation through Option Simulation
Authors: Jafarizadeh B. , Bratvold R. B. 
Published: October 2009

Abstract
Despite the early enthusiasm, real option valuation (ROV) has hitherto failed to "revolutionize" the way companies value their uncertain real-world assets. The reluctance to embrace ROV is largely due to its complexity and limited applicability to real-world problems.
In this paper, we will introduce, discuss, and demonstrate the potential of one of the most promising ROV techniques: Least-Squares Monte Carlo Simulation (LSM). LSM is a significant step in overcoming the limitations in valuation techniques. It is particularly powerful when investment decisions are a function of multiple uncertain factors and when compounded options which may be exercised at any time exist. The paper will also include a real-world application, illustrating the power and flexibility of the LSM method.
Developing and using a fit-for-purpose ROV model for a realistic investment opportunity is no simple task. However, the result of an ROV is not only an estimated value that includes the value of flexibility, but a complete strategy map showing the optimal choices as uncertainties are resolved. This, together with the creative thinking required to come up with valuable options and identifying the key uncertainties, creates insight and clarity for the decision-makers.
Oil, Natural Gas and NGL Endowment in North, Central and South America
Authors: Aguilera Roberto F. , Aguilera Roberto 
Published: October 2009

Abstract
This study uses the USGS 2000 world petroleum assessment as a starting point. Then it uses a previously defined variable shape distribution (VSD) model for estimating the endowment of oil, natural gas and natural gas liquids (NGL) throughout North, Central and South America.
Use of the VSD model is validated by an excellent fit with actual data, supported by coefficients of determination (R2) equal to 0.98 or greater. The study includes endowments in petroleum provinces not assessed previously by other organizations. Endowment, as defined by the USGS, refers to the sum of known volumes of hydrocarbons (cumulative production plus remaining reserves) and undiscovered volumes. Petroleum is the sum of oil, gas and NGL.
The importance of North, Central and South America is highlighted by a hydrocarbon output during 2007 that accounted for 25% of the world oil production and over 31% of the natural gas production.
It is concluded that there is a large petroleum endowment in North, Central and South America that will last for several decades and will help to contribute significantly to the energy needs of these regions. It is recommended to actively pursue research and development of this endowment.
A Molecular Dynamics Study on Natural Gas Solubility Enhancement in Water Confined to Small Pores
Authors: Campos Mery Diaz , Akkutlu I. Yucel , Sigal Richard F. 
Published: October 2009

Abstract
Unconventional natural gas reservoirs are a major source for the global energy market. Unconventional gas reserves generally are considered to consist of a volumetric component, hydrocarbons stored in the pore space as free gas, and a surface component, gas adsorbed on the large surface area of these microporous systems. A second volumetric component, gas dissolved in the formation water, is generally not considered. For such reservoirs, free gas is quantified by modifications of standard reservoir evaluation methods. Physically adsorbed gas has generally been quantified from laboratory studies to establish the equilibrium adsorption isotherms. Based on bulk solubility calculations, the amount of dissolved gas in water, however, has not been considered important. Our group has recently performed a theoretical study which, for reasonable values of its parameters, predicts that methane solubility is enhanced in microporous media. The implication of this is that the dissolved gas in the formation water may represent a significant portion of the total gas reserves in unconventional reservoirs. Best quantification of this result and insight into this solution chemistry problem should ideally come from theoretical studies at the pore-scale, particularly from molecular-level simulations and the subsequent free energy change calculations accompanying dissolution. In this paper, we examine natural gas solubility enhancement in water residing in a graphene slit-pore with a length-scale on the order of ten nanometers, namely a micropore, using an analytical approach and molecular dynamics simulations. The solubility of methane in water is estimated under controlled temperature condition using the test particle insertion method with the excluded volume map sampling. The results indicate that the methane solubility in the pores is improved significantly (typically, one order of magnitude larger), compared with that in the bulk phase, i.e., in the absence of pore walls. The enhancement is further investigated under varying force-field conditions due to pore-wall surface potential, namely hydrophobicity and found that the solubility is extremely sensitive to small pore wall wettability. The work is a fundamental approach to better understand the unconventional gas reservoirs, and important for the estimation of gas reserves.
High Dogleg Rotary Steerable System: A Step Change in Drilling Process
Authors: Bryan Sonny , Cox Joe , Blackwell Dennis , Slayden Fred , Naganathan Siva 
Published: October 2009

Abstract
Directional drilling has long evolved from the days of Drilling primarily with rotary assemblies, motors and turbines to regular use of rotary steerable systems (RSS). Spears estimate that RSS decreases drilling time by 50% on average (no sliding intervals) and overall well time by 25% (good quality borehole enabling smooth casing and wireline runs). However current rotary steerable systems available in the market have several limitations:
Maximum Dogleg severity capability for RSS drilling 8.5in or 8.75in hole sizes from major service companies is about 6.5 to 8° /100ft in normal formations. In case of soft formations or excessive borehole enlargement these figures drop significantly and BHA is tripped out of hole for running PDM.
Most RSS require a cement plug to be in place to perform consistent and reliable sidetracks. This results in additional time and trips for the operator.
Controlled kick off from vertical is not possible with RSS that require a gravity vector defined to seek TF. This results in quick course corrections and higher T&D.
Steering through highly inter-bedded formations close to horizontal is challenging to conventional RSS due to limited DLS resulting in POOH.
This paper discusses the new generation of fully rotating RSS that has twice the dogleg severity capability of any current RSS systems (up to 15°/100ft). This new technology enables deeper Kick off lowers the horizontal displacement significantly (by 50% or more compare to current RSS), decreases overall measured depth and improves ROP. In addition to this, this new technology has proven its directional versatility by performing open hole sidetracks, saving cost and operating times. It has repeatedly demonstrated its ability to kick off accurately from vertical, land the well precisely on target depth and execute closed loop trajectory controls while drilling lateral sections.
A number of case studies are covered in this paper with results from the field trials of this unique technology. With these capabilities every driller's dream to drill more complex well profiles in single run without the need to trip out of hole with time and cost savings will become reality.
Mechanistic Modeling of Solids Separation in Solid/Liquid Hydrocyclones
Authors: Severino Jose G. , Gomez Luis E. , Wang Shoubo , Mohan Ram S. , Shoham Ovadia 
Published: October 2009

Abstract
Hydrocyclones have been used for many years for removing solids from continuum liquid media in the Mineral, Chemical, Petroleum, and Environmental industries; among others. In oilfield applications, the Solid-Liquid Hydrocyclone (SLHC) has emerged as a sound technological and economical alternative to conventional filtration systems where space, efficiency, reliability and continuous operations are critical. The SLHC is particularly attractive in offshore, subsea, and water injection applications; and other oilfield operations. Early and effective removal of solids in pipelines and process equipment help prevent erosion and premature failures that are costly and pose serious health, safety or environmental hazards.
To date, hydrocyclone design has mainly relied on empirical experience and, most recently, on costly and lengthy CFD simulations. The main objective of this work is the development of a mechanistic model for practical, yet reliable, SLHC design. The proposed model is capable of describing the hydrodynamic flow phenomenon inside the hydrocyclone, enabling the prediction of continuous-phase swirl intensity and the velocity profile used in determining particle trajectories, and hence, the Grade separation efficiency curves. The model is validated against oilfield experimental data run under a wide range of conditions and equipment configurations. Model agreement with Global and Grade separation efficiency data is 94.7% and 88.2% respectively.
A Study of a Low-Frequency Downhole Hydraulic Pulsing Cementing Device and Its Field Application
Authors: Nie cuiping , Towler Brian Francis , Ye Dengsheng 
Published: October 2009

Abstract
A down-hole pulsed pressure device to improve the quality of cement bonds during primary cementing has been developed. The prime purpose was to control gas and water channeling and enhance the cement slurry displacement efficiency, especially in holes with a small annular space, and in holes with large washed out spaces occupied by mud-cake and in gas wells that are susceptible to gas channeling. These problems are difficult to treat with chemical cement agents.
It is shown that pulsing the curing cement can improve the cement slurry hydration, shortening the time between the initial and final cement gelation and abating the slurry weight loss effect. Our experiments show the pulsing frequency is best between 10–30 Hz and the pressure amplitude should be less than 5 MPa.
The device is highly innovative, is easy to engage to the casing string (under the float collar) and has no effect on the casing design. It does not cause failure during cementing, and does not alter the traditional cementing technology.
It has been applied to gas wells in several fields in Sichuan province in China. The pilot well had 11 gas layers and is 4180m (13,714 ft) in depth, and the hole was prone to lost circulation (1.09g/ cm3 mud) and cave in. The cemented well interval was drilled with a 152.4mm (6") bit and cased with a 127mm (5") liner. There are troublesome formations in the interval that caused difficulties in logging and while running the liner. The down-hole pulsing generator worked well with the 1.50g/cm3 cement slurry, but due to the complicated hole conditions the displacement was not finished when the liner became plugged with cement. But after drilling out the cement plug, the CBL and other logs showed the cement quality had been enhanced 50% compared to the offset wells. Then in application to another three wells we also achieved significantly improved cement bonds. So it has been verified that this device can significantly improve cementing, and is easy to apply in the field. We intend to continue to apply it to wells with troublesome formations and to all gas and oil wells with cementing problems.
An Intelligent Platform to Manage Offshore Assets
Authors: Piovesan C. , Kozman J. 
Published: October 2009

AbstractFor offshore platforms and other facilities, intelligent asset management must include proactive monitoring of surface equipment. Studies (Athens Group, 2009) show that up to 20% of the non-productive time (NPT) experienced by a deepwater rig can be the result of control system failures on drilling or production equipment. But similar failures can impact the fixed surface equipment on the rig floor that can also shut down drilling or production operations. Timely management of the complex, software-dependent control systems from multiple equipment vendors on the rig floor can therefore be a major determinant of productivity for intelligent oilfield implementations. The primary goals of the Intelligent Platform (or I-Platform) are to reduce equipment downtime and personnel-on-board (POB) requirements while increasing reliability, safety, regulatory compliance and environmental responsibility. This requires defining operating envelopes that optimize equipment usage for costs and efficiencies, allowing early identification and intervention for pending equipment outages and enabling root-cause failure analysis that takes into account multiple environmental factors. The use of intelligent platform technology has already been proven for subsurface drilling and production data streams and has reached a competent level of capability maturity (Heiberger, 2009). The I-Platform solution applies best practices derived from numerous digital oilfield case studies to fixed surface equipment in order to reduce NPT. This solution is an end-to-end implementation for surface equipment that brings together mission-critical capabilities developed and already being deployed for downhole operations. It utilizes unique data analysis tools with artificial intelligence algorithms for codifying existing equipment expertise into business rules such as neural networks and self-organizing maps. Results of the data mining and analysis are delivered in a role-based and easily configurable visual dashboard for multiple aggregated data streams. A recent prototype installation utilizes data streams from a major offshore drilling contractor with a versatile fleet of mobile offshore drilling units and an operational performance center at a leading oilfield service company to demonstrate the viability of this approach for both offshore and remote onshore operations. The success of this proof of concept demonstrates that disparate data from multiple equipment vendors can be gathered from remote locations, analyzed and distilled into actionable items, and displayed in order to support proactive decisions by a distributed pool of subject matter experts.
Effect of Material Balance on Well Test Analysis
Authors: Madahar Amit , George Stewart , Gringarten A. C. 
Published: October 2009

Abstract
This paper provides a new definition to pseudo-time that incorporates the effects of formation compressibility and residual fluid compressibility, as the reservoir depletes, into well test analysis. The new definition of the pseudo-time can be incorporated into the existing system by using a correction factor that is applied to conventionally defined total system compressibility. The new definition of pseudo-time determines the final average reservoir pressure more accurately even at high degree of depletions of the reservoir. This study also addresses the errors in gas reserves estimation when using conventionally defined total system compressibility, which may have a substantial economic effect.