bluuebunny/crossref_metadata_2025_split huggingface dataset:
From Issues to Solutions – Introducing the Multi Function Logging while Drilling Tool for Reservoir Characterization in the Greater Burgan Field of Kuwait Oil Company
Authors: Al-Azmi Khalid H. , Al-Enezi Hamdah , Kotecha Rohitkumar , Al-Sabea Salem , Archibong Ekpo , Al-Khaledi Ahmed , Oyeyemi Oluwafemi 
Published: May 2009

Abstract
The Greater Burgan Field consists of three sub fields (Ahmadi, Burgan and Magwa). Drilling commenced in this field in 1938 and it went on stream in 1946. Most of the production comes from a giant oil reservoir in a siliciclastics depositional environment. This giant oil reservoir has intercalating sand shale sequence with the upper part having mixed lithology. Co-existing together are argillaceous glauconitic sandstones, calcite, dolomite and anhydrite with pyrite and siderite.
With increasing demand of oil in the world, it has become necessary to improve oil production. As a result, the various field development assets of Kuwait Oil Company (KOC) are tasked to increase the number of horizontal wells in order to access thin reservoirs in the field. This has prompted these teams to increasingly rely on Logging While Drilling (LWD) services as well as improved geosteering practices in order to efficiently access the untapped energy resources buried several thousand feet below the earth;s surface.
Evaluating these wells becomes an issue especially if the wells are drilled in areas that might add to the reserves of the asset. Resistivity anisotropy is a major issue, especially if it occurs with influence of other bed boundary effects like resistivity of adjacent beds or polarization horn effects. Water coning issues in the field makes it even worse to interpret the resistivity data as they become spiky. Complexity of the resistivity signature in a mixed lithology environment makes petrophysical evaluation difficult.
With the recent introduction of the Multi-Function LWD tool where most of the basic measurements are collocated in one LWD collar, it is now possible to make measurements with similar environmental influence prior to significant invasion of the formation. In addition, the introduction of capture gamma ray spectroscopy and formation sigma in real time has improved the petrophysical evaluation of this complex resistivity environment with mixed lithology in wells that are difficult or even costly to consider wireline logging.
This paper aims at highlighting horizontal well drilling issues occasionally encountered in the Greater Burgan Field and the recent introduction of the Multi-Function LWD service to help address these formation evaluation issues.
Pressure and Temperature Effect on Petrophysical Characteristics: Carbonate Reservoir Case
Authors: Benzagouta Mohammed S. , Amro Mohammed M. 
Published: May 2009

Abstract
The conducted study is aimed to investigate on temperature and pressure variation applied to carbonate reservoirs and their petrophysical characteristics mainly permeability.
In the laboratory, intensive runs of flooding experiments were carried out at different effective pressure up to 4000 psi and temperature reaching 100 °C using carbonate samples from Middle East reservoirs. This investigation was aimed to examine fluid circulation behavior coupled to probe on textural examination of the carbonate samples. This latter was achieved by the use of ordinary microscope and scanning electron microscope (SEM).
Results indicated that permeability reduction can be controlled by variation in pressure and temperature: permeability reduction corresponds to pressure and temperature increase. It has been found that a wise permeability reduction start to be recorded above a value of 50 °C with reference to initial permeability at 25 °C. Furthermore, the permeability reduction has reached 59 % at an effective pressure of 4000 psi and a temperature of 100 °C compared to initial permeability at 725 psi and at 25 °C. According to the overall results, the effect of temperature on permeability reduction in the applied carbonate samples is as important as that of the effective pressure.
Various processes can be suggested for such diverse changes. However, packing and compaction leading to rock deformation and elasticity rock property remain among the main factors responsible for such statement. In addition, and based on the experimental and textural work led, it is important to notify that no formation damage has been notified.
Advances in Sampling Methods Using a New Dual Port Straddle Packer Pumpout Tester in One of Saudi Aramco's Oil Fields
Authors: Silva Andre , Palmer Richard , Hajari A. A. , van Zuilekom Tony , Engelman Bob , Rabbat Ashraf 
Published: May 2009

Abstract
Collecting high quality fluid samples with a pumpout wireline formation tester (PWFT) configured with a conventional probe in carbonate reservoirs is often a challenging operation. Straddle packers are far more suitable than probes for sampling low permeability, heterogeneous carbonate reservoirs. A large volume of whole mud is trapped between the packers when they are initially inflated. The mud must be partially voided before formation fluid begins entering the packed-off interval. Before pumping begins, the near borehole region is occupied with contamination as a result of drilling overbalance and mud filtrate invasion. Uncontaminated reservoir fluid begins entering the packed-off interval after an adequate volume of contaminated fluid has been removed. Water-based mud filtrate (WBMF) and crude oil tend to separate in the packed-off interval as a result of fluid density difference and immiscibility. Moreover, a water oil interface forms at some level within the packed-off interval. As pumping continues, this oil/water fluid contact levels off at the inlet port, and both water and oil will continue to flow through the inlet throughout the sampling process. This complicates fluid identification and makes obtaining a low contamination single phase sample problematic. By taking advantage of a dual inlet port straddle packer and a new fluid density sensor, it is possible to verify the occurrence of fluid segregation within the packed-off interval. The new dual port straddle packer design enables independent opening and closing of the top and bottom ports to observe fluid segregation. By sequencing these port valves and sample chamber valves, we demonstrate how low contamination samples are obtained faster than with a single port system.
This paper provides a description of the new sampling techniques based on samples collected in a Saudi Aramco oil field, as well as examples that show the fluid segregation effect between the packers. It compares the pumping times of a straddle packer vs. an oval pad pumping in similar reservoir conditions. This paper also describes the process used to collect both water and oil samples and the challenges associated with sampling at the oil/water contact (OWC). It also presents the lab results that verify the low contamination level samples obtained by using the new methods.
World's First 3-7/8" Multi-lateral Short Radius Re-entry Completed With Ultra-Slim ICD System
Authors: Al-Mumen Adib A. , Al-Essa Ghassan A. , Infra Morry , Bu-Zaid Sami , Salerno Giovanni 
Published: May 2009

Abstract
Saudi Aramco has successfully used inflow control devices (ICDs) in the past few years to equalize production profile and enhance recovery from new and re-entry horizontal wellbores. This approach was limited to hole sizes of 5-1/2" hole and bigger. These success results led to working over old wells in mature fields, originally completed with 4-1/2" liners/casings, with ICD completion systems to prolong production life.
The paper will describe the drilling, completion and successful installation of the world's first ultra slim-hole ICD system, run across the mother bore of a short radius re-entry 3-7/8" tri-lateral horizontal section. The paper will highlight the following: The directional plan approach used to ensure the ICD completion will go past the branch out points, all the way to the total depth of the mother bore.The completion equipment, which consisted of ultra slim ICDs and swell packers for zonal isolation.Operational problems encountered and corrective actions for future re-entries.
The paper's summary will show the production performance of the well and how the completion was successful in compartmentalizing and distributing the flow from the mother bore and other laterals.
Changes in Shale Strength Resulting from Interaction with Invert Emulsion Drilling Fluids
Authors: Hemphill Terry , Duran William , Abousleiman Younane , Tran Minh , Nguyen Vinh , Hoang Son 
Published: May 2009

Abstract
Most wellbore stability problems occur while drilling shale intervals. Although the drilling industry invests large amounts of time and money each year to deal with the problem, the interaction between drilling fluids and shale is complex and not well understood. Generally speaking, fewer wellbore stability problems occur when drilling with invert emulsion drilling fluids (IEF) than with water-based drilling fluids (WBF). In this paper, the theory governing the interaction between shales and invert emulsion drilling fluids is briefly reviewed.
A new testing device developed by the University of Oklahoma was used to study changes in rock strength of shale cores exposed to invert emulsions. Two shale samples, one from a deepwater environment and another from an onshore environment, were exposed to invert emulsions having varying chemical activity (water phase salinity) levels. The stresses required to fail the samples were directly measured under in-situ conditions. The results showed that under some conditions the invert emulsion strengthened the samples and under other conditions the shales were weakened. These results are interpreted using current osmotic pressure and membrane efficiency theory of invert emulsions.
Using a set of in-situ drilling and wellbore stress conditions, traditional elastic wellbore stability modeling is used to predict changes in pore pressure at the wellbore wall as a function of changes in invert emulsion chemical activity. Porochemoelastic modeling is also performed to predict changes in shale pore pressure as a function of time. The modeling results are compared to the shale strength data obtained in the laboratory.
Lastly rock strength measurements of shales exposed to IEF are compared to those exposed to WBF having the same chemical activity (water phase salinity) levels. The differences in performance are explained in terms of osmotic pressure and membrane efficiency theory.
With the laboratory and computer modeling results, the drilling engineer can better appreciate the effect of invert emulsion interaction with shales, which can enable better planning of future wells, especially those having narrow safe drilling windows.
Utilizing Expandable Casing Clad Enabled Short Radius Sidetrack in Wells with Casing Leaks
Authors: Al-BinAli Ali N. , Al-Baggal Zaki A. , Al-Mumen Adib A. , Aubed Yaser 
Published: May 2009

Abstract
Short radius re-entries are very common in Saudi Aramco. Short radius is the fastest and generally most cost effective way to deliver reentry wells whenever vertical wells are converted into horizontal wells. A casing leak across Arab-C formations is a common problem in some onshore fields. Arab-C formation is a high-pressure water bearing zone. Arab-C is located right above the cap rock of the pay zone. When leaks develop, water starts to flow from the high pressure zone to the pay zone (downhole cross flow) and the well will stop producing oil.
This paper will describe the use of expandable casing clad to repair wells with casing leaks across the high-pressure zone. In such wells, the leak was located across Arab-C in production liner. Then, the leak was squeezed off with cement. After that, the casing window was milled below the leak and a short radius curve section was drilled without penetrating the pay zone (Arab-D). Next, the expandable casing clad was utilized to enable drilling the low-pressure pay zone with low mud weight.
Utilizing this technique enabled Saudi Aramco to drill short radius sidetracks while insuring integrity of the well, provide Geosteering in the pay zone and facilitate the option to run flow control/isolation systems. By drilling such wells as short radius re-entries, long radius sidetracks with open hole expandable liner option were avoided. Consequently, significant rig time and cost savings were achieved. After the success of this technique, short radius drilling was still carried out with wells that had casing leaks, and the leaks were stopped.
A Window of Opportunity: Using Real-Time Data During Casing Exits
Authors: Joppe Lambertus , Wilson Steve B. , Fernandez Raj 
Published: May 2009

Abstract
Today's reserves are often stranded in deep, complex reservoirs and, due to economic or environmental constraints, sometimes have to be connected from a single drill site, resulting in wellbore construction methods such as extended-reach drilling (ERD) and multilaterals. Casing exits often play a crucial part in these types of wellbore construction methods. Milling a long window with low dogleg severity is the key to success since every subsequent run into the wellbore – rotary steerable system, liner and completion systems – will have to pass through the window unobstructed. The successful execution of a casing exit based on surface parameters alone becomes more and more challenging as depth and deviation of the application increases.
A system has been developed that measures all the physical parameters downhole at the window-milling assembly itself, and transmits them to surface for rig-site and remote viewing, enabling real-time control of casing exit operations. The system captures and processes all the milling parameters downhole and then uses measurement-while-drilling mud pulse telemetry or stiff-line / wired pipe to send selected and critical information to surface. The window-milling process can be enhanced by monitoring dynamic behavior such as mill vibration, weight on bit and bending moment to make real-time decisions and reduce risk and nonproductive time (NPT).
This paper describes the downhole performance sub technology and closed-loop control system, and demonstrates by a number of case histories the risk-reduction value of monitoring the downhole parameters in real time. The case histories presented includeboth drillpipe-deployed as well as coiled-tubing-deployed casing exit systems.
Successful Mitigation of Time-Dependent Shale Instability in Khafji Field through Drilling Fluid Design Optimization
Authors: Tan Chee Phuat , Qadmani Marwan Ahmad , Povstyanova Magdalena , Mohiuddin Mohammed Ahmed , Rahim Mohd Helmi Abd 
Published: May 2009

Abstract
Al-Khafji Joint Operations is developing the offshore Khafji Field in the X-Neutral Zone by drilling horizontal wells. These wells encounter shale formations namely Ahmadi Shale and Wara Shale before reaching the pay zones, and Intermediate Shale between KB-1 and KB-2 Sands. While drilling these shale formations, severe time-dependent wellbore instability problems due to shale sloughing were experienced. These problems have led to several stuck pipes and sidetracks.
A drilling fluid optimization study was conducted on seven offset wells in the field in order to evaluate the potential time-dependent wellbore stability mechanism(s) in Ahmadi Shale, Wara Shale and Intermediate Shale, to define appropriate mud type, salt type and concentration, and to develop solution and strategy to mitigate and/or manage the wellbore instability problems.
End of Well reports of selected offset wells were reviewed, and numerous time-dependent wellbore instability-related drilling events in Ahmadi Shale, Wara Shale and Intermediate Shale were identified. Both mud pressure penetration and chemical potential mechanisms were considered in the back-analysis of time-dependent wellbore instability in the shales. The analysis showed that the instability was attributed to insufficient salinity in the drilling fluid which resulted in pore pressure increase due to the mud pressure penetration mechanism being not counteracted by the chemical potential mechanism. As a consequence, the pore pressure increased near the wellbore wall which reduced the effective mud support and led to unstable wellbore condition.
Based on the drilling fluid optimization study together with input from mechanical wellbore stability analysis, recommendations on optimum drilling fluid design were made for drilling Ahmadi Shale and Wara Shale which were successfully applied in a planned horizontal well in the field.
Design of New, Fit-For-Purpose, Downhole Positive Displacement Motor Improves Reliability and Enhances Performance in 16-in. Vertical Sections
Authors: Azizov Azar , Hilthon Karl , Mounzer Fadi , Kent David 
Published: May 2009

Abstract
Saudi Aramco operates several deep gas reservoirs in the Kingdom of Saudi Arabia (KSA). Both vertical and horizontal K2 gas development wells have long 16-in. vertical sections. The 16-in. section is drilled as quickly as possible through several mid-depth hydrocarbon reservoirs to a competent seat in a dolomitic limestone. Since this section is fairly long (±5,000 ft) it represents one of the biggest challenges in the continuous drive for better rate of penetration (ROP) as well as reliability of downhole drilling assemblies.
These sections are typically drilled with various positive displacement motors (PDM) in a simple performance bottomhole assembly (BHA) setup with two roller-reamer type stabilizers to mitigate mechanical stuck pipe risks. Drilling through the interbedded formations with varying hardnesses using very aggressive 16-in. bits has proven to be challenging in terms of wear and tear on the drilling motors. Damage to the motors, such as stator chunking, bearing failures and even catastrophic connection twistoffs have occurred during these drilling operations.
One service provider currently uses 9½-in. motors in the 16-in. wellbores. To address tool integrity issues, the service provider upgraded to their standard offering, 12¾-in. motors. While incidences of housing and stator failure were eliminated, the combination of large, high flow rate tools in a land-based operation has not delivered the required performance on bottom. The drilling rigs currently employed for gas development drilling were not capable of pumping more than 1,300 gpm while optimum performance from the standard 12¾-in. motor comes with flow rates above 1,500 gpm. As a result, bit speed was too low, and ROP did not meet or exceed the 9½-in. motor runs and the standard 12¾-in. tools did not find widespread acceptance from the client.
A new, more robust 12¾-in. motor was developed, which was also designed to provide higher rotary speed output at available flow rates and pressures. To evaluate the performance of this new motor, a drilling dynamics diagnostic tool was run in a field testing program.
To date, several runs have been made with the new 12¾-in. motor in various fields in the Kingdom of Saudi Arabia. Various BHA incorporating different motor configurations and newly designed bits have been used. The drilling dynamics diagnostic tool was positioned directly behind the motor to obtaining a better understanding of the BHA and bit response for the various configurations.
This paper will focus on the significant reliability and performance improvements achieved through the introduction of the new motor, which was specifically designed for this challenging environment.
Minimizing Wellbore Damage in a Sandstone Reservoir Using Effective Mud Management Practices
Authors: Rabaa Ali S. , Phillips James E. , Al-Ammari Saleh M. , Mohamed Monir 
Published: May 2009

Abstract
Inducing formation damage in sandstone reservoirs through poor drilling fluids management is a crucial factor that can affect well productivity. An integrated team assigned to manage drilling horizontal producers for field development, developed a mud management plan to monitor drilling fluid properties and maintain mud system specifications to minimize formation damage in the field's sensitive sandstone reservoir. This paper discusses the implementation of the engineered oil-based drill-in fluid, particle size monitoring, and drilling and completion methods designed to minimize reservoir formation damage and help maximize well productivity.
A particle size distribution (PSD) analyzer was used in the field to monitor the PSD values of the particulates in the drill-in fluid (DIF) while drilling the sandstone reservoir. Core samples were selected and analyzed using a scanning electron microscope (SEM) to determine an average pore size value.
A diesel-based DIF was specifically designed to minimize formation damage. The DIF was formulated with a 70/30 oil water ratio and was treated with a sized calcium carbonate bridging agent to help minimize spurt/total loss. The engineered bridging agent was added to prevent formation damage that results from the invasion of fines. Overbalance pressures were also minimized to avoid the risk of differential sticking.
For better bridging results, the D90, D50 and D10 particle size distributions were instantaneously maintained in the programmed range while drilling the entire sandstone pay section with controlled rates of penetration (ROP). The % of drill solids as a function of total solids was also maintained at low levels with the use of centrifuges and addition of whole treated mud. Upon reaching the total depth (TD), the bottomole assembly (BHA) was changed to a reaming assembly and the entire open-hole section was reamed to TD.
After making a wiper trip, the operator tripped back to bottom without pumping to simulate hole conditions that would occur while running screens. Once the open hole was deemed in good condition the well was displaced to a solids-free invert emulsion mud maintained at the same density as the DIF. This fluid was circulated over a 230-mesh screen prior to running the screens to ensure that all fine sand and excess filter cake were removed.
To date, 26 wells have been successfully drilled and completed with sand screens using the abovementioned methodology. Testing results of the first three wells indicated minimum skin damage and good and stable production rates.
Multi-Stage Acid Stimulation Improves Production Values in Carbonate Formations in Western Canada
Authors: Baumgarten Dan , Bobrosky Doug 
Published: May 2009

Abstract
Over the past few years, a new multi-stage, multi-jet fracturing technology has improved the acid fracturing of the Wabamun formation located in south central Alberta.
The Crossfield member of the formation, found in the Swallwell field, has a large original oil and gas reservoir with low recovery factors to date of 2.4% for oil and 5.2% for natural gas. A 1% increase in recovery factors would yield an additional 875,000 bbls and 851,000 mcf of gas.
Use of multiple mechanical isolation points in the new technology has demonstrated average initial production increases of 77 to 102% and final production increases of 12 to 28% compared to historical wells. The micro to very fine crystalline dolomite of the Crossfield member has average permeability ranges from 0.1 and 0.3 mD; therefore, acid stimulation is required in order to economically extract the resource.
This paper will discuss the planning and design processes that led to the implementation of the multi-stage, multi-jet technology. It will outline the lessons learned during deployment of the completion, and will highlight the stimulation treatment execution and post-stimulation results. The text will detail examples from the case studies and will outline the benefits of this technology.