Smith, Chris (Condor Petroleum Inc.) | Dehghani, Ali (Condor Petroleum Inc.) | Hatcher, W. B. (Condor Petroleum Inc.) | Mukhambetpaizov, Yesset (Condor Petroleum Inc.) | Askarov, Bakhtiyar (Condor Petroleum Inc.) | Burg, George (Burg GeoConsulting Inc.)
This Paper describes the challenges and successful application of Inflow Control Devices ("ICDs") combined with sand control screens for horizontal wells. The ICDs were installed to reduce water and gas coning at the Shoba field. Shoba was the first field in Kazakhstan to use ICD technology and the first field in the Pre-Caspian basin where shallow horizontal wells were drilled.
The Shoba field is located within the Zharkamys West 1 block in western Kazakhstan. The Triassic-age sandstone reservoir consists of sweet 34° API oil. The field was initially developed with seven (7) vertical wells. However, high vertical permeability, in combination with high gas and water mobility, resulted in excessive gas and water breakthrough that marginalized the field's economics. An alternate development plan utilizing ICDs and horizontal well technologies was necessary to enhance field commerciality. This project presented numerous challenges. Since the field is relatively small and wells of this type had not been drilled in the region, there was little opportunity for a "learning curve", no margin for excessive cost over-runs, or well failures. Some of the issues overcome that will be presented: ICD design and selection considerations Wellbore instability for shallow horizontal wells Isolation of a sizable gas cap above the productive oil zone Plugging of the sand control screens during their placement Premature gas or water coning
ICD design and selection considerations
Wellbore instability for shallow horizontal wells
Isolation of a sizable gas cap above the productive oil zone
Plugging of the sand control screens during their placement
Premature gas or water coning
Shoba's first two horizontal wells were drilled and completed on time and under budget, with early results confirming a reduction of water and gas coning. A significant increase in production rates has also been realized. Given the project's initial success, additional horizontal well development drilling continues.
This paper portrays the advantages of utilising an 18-month "Fast-track" or Accelerated Assistant Drilling's Program for young people new to the Industry employed by a major drilling company in South East Asia.
The challenge was to educate young people of different backgrounds, nationalities (Thai, Indonesian, Malaysian and Bruneian) whose practical and theoretical skill capabilities and language abilities in Tender Assist Drilling who have never come across such equipment before so that they clearly understood the design and functionality of their equipment on-board their specific rig.
Given that Drilling is not an easy subject for people to understand (especially those who are new to the Industry) the task of writing material especially suited for such people is not as easy as it may seem, since the bulk of material available on the subject is at too high and too complex a level. Also, there are very few books written specifically on the subject of Tender Assist Drilling as there are several units, which have to be addressed: – 1) The Tender and Anchor Winches; 2) The Umbilicals and Lines and 3) The Drilling Equipment Set mounted on the platform.
An 18-month E-Learning, Offshore and Classroom Training Program was considered the ideal solution for this training since, through being bespoke, it could be clearly and unambiguously written. It could also dove-tail perfectly with the new IADC "Wellsharp" and IWCF well control training programs and the OGP Report No.476, which recommends certain enhancements to well control training.
That every trainee scored high marks in the various sections both onshore and offshore is testimony to the fact that such a program is indeed the perfect training aide for young people coming into the industry for the first time. As a result, it is seen as an ideal cost-effective method for future training courses.
Al-Ajmi, Khaled (Kuwait Oil Company) | Al-Hamadi, Ebrahim (Kuwait Oil Company) | Baqer, Yousef (Kuwait Oil Company) | Al-Suliman, Mishari (Kuwait Oil Company) | Al-Mutairi, Abdulwahab (Kuwait Oil Company) | Singh, Anilkumar (Kuwait Oil Company) | Al-Sarraf, Abdullah Baqer (Kuwait Oil Company) | Al-Sairafi, Fatma Abdulatif (Kuwait Oil Company) | Fayed, Moustafa (National Oilwell Varco) | Khalil, Karim (National Oilwell Varco) | Khalil, Ahmed (National Oilwell Varco)
This paper will discuss the deployment of the concentric dual diameter fixed cutter bit technology which was introduced in January 2015. The bit was deployed and tested four times in a vertical application and S-shape wells in Burgan Field, South of Kuwait and achieved the fastest penetration rate in the application.
The concentric dual diameter bit is composed of a smaller pilot and a larger reamer section, where the reamer section dictates the final drill size. Conventional fixed cutter bits take very little advantage of stress relieving the rock, as it only affects the borehole wall. Concentric dual diameter technology bits are able to initially drill with a leading smaller pilot section efficiently to relieve the stress of the rocks. Subsequently, the reamer section removes the stress relieved rock with lower mechanical specific energy compared to regular fixed cutter bits, giving it the advantage to generate higher penetration rates. Another advantage of the concentric dual diameter technology bits is the stability of the bit, since two gauge sections are available to be in constant contact with the borehole while drilling.
The first 12 ¼ in. concentric dual diameter technology bit in conjunction with a packed rotary BHA was tested in a vertical application in the Burgan Field, South of Kuwait. The bit was able to deliver improved performance by drilling two wells from shoe-to-shoe to section TD of 1372 ft with an ROP of 152.4 ft/hr where the lithology consisted of shale and sandstone.
The performance capability was confirmed when the second bit drilled two wells shoe-to-shoe to sections to a TD of 2263 ft with ROP of 161.6 ft/hr. and achieved top record runs in south Kuwait for vertical applications and S-shape wells and consisted of similar lithology of shale and sandstone.
The 12 ¼ in. concentric dual diameter was able to surpass the average rate of penetration for the same application in the Burgan Field by 100% saving the operator drilling time and making the concentric dual diameter bit design the top performing drill bit in the field.
This study investigates, theoretically and experimentally, the effect of conventional and new chelating-agent-based acidizing fluid systems on carbonate formations. An initial assessment showed that an existing semi-empirical model used for hydrochloric (HCl) acid systems was not suitable for predicting wormhole growth and penetration for chelating agents.
With recent advances to acidizing and stringent environmental regulations, chelating agents have begun to replace conventional acid systems for well stimulation. They are more environmentally acceptable and can work in high-temperature wells. One crucial aspect for successful well stimulation of carbonate matrix acidizing is acidizing models. Yet, there have been few attempts to model wormhole growth and penetration for these newer chelating agents.
A semi-empirical mathematical model is proposed for chelating agents based on published experimental data. The results were compared with HCl acid systems.
The predicted wormhole growth was in good agreement with laboratory data for a wide range of temperatures and concentrations. A comparative study with chelating-agent and HCl-acid systems is also discussed. Results showed that pore volume to breakthrough (PVbt) for the chelating-agent-based system increased more steeply compared to the HCl-acid-based system with injection rate. This would translate into higher pumping volumes in the field for a given wormhole penetration if not optimized. This could be attributed to the slower reaction rate of the chelating agent and might require adjustment in transport phenomena for optimized treatment design.
The model developed in this work should help field engineers design treatments with optimum rates and volumes, helping minimize the cost of stimulation treatments. It should also further facilitate understanding of the wormhole formation mechanism for chelating agents.
While planning a wildcat exploration well, an operator faced formation depth uncertainty as a result of poor seismic imaging as well as limited offset pore pressure and fracture pressure data. A steep pressure ramp was anticipated at some depth below surface casing, and casing design included a 16-in liner to secure this interval. To properly evaluate and understand the lithology and pressure while drilling would require high-quality LWD data, but it was also essential that the liner and casing could be fully run to the bottom of the hole. Underreaming near the bit while drilling would compromise the LWD data, but underreaming above the LWD tools would not enable the casing to be fully run to bottom. Two hole-enlargement-while-drilling (HEWD) BHAs with the option for rathole elimination (RHE) were proposed and enabled these objectives to be efficiently achieved without compromise. A combined HEWD and RHE BHA is not new in the industry, but it is challenging in large hole sizes. With multiple cutting structures in the BHA, drillstring dynamics become complex. The resultant vibration and shock can lead to diminished drilling performance, or even failure of BHA components.
A prejob finite-element analysis (FEA) modeling simulation was used to investigate the dynamic drilling behavior of the initially-planned BHAs. The simulation results from initial BHA design predicted high vibrations. A BHA optimization analysis was then conducted to determine the most favorable BHA configuration for effective LWD tool placement and minimized vibration issues, taking into account the BHA geometry and stabilization points, cutting structures, and formation type. The simulation results from the final BHA exhibited a significant reduction in shock and vibration levels. Suitable drilling parameters were identified, and hydraulics simulations were performed to ensure that both the HEWD and RHE underreamers could be reliably actuated.
The operator implemented the recommended BHAs, cutting structures, and parameter roadmaps on both the 17-in × 20-in and 14¾-in × 17½-in sections, and the solution successfully drilled 501-m and 605-m intervals, respectively. Each interval was drilled and enlarged in a single trip. Both HEWD BHAs exhibited low levels of vibration during the original underreaming, enabling quality LWD data to be obtained. After maximizing section depth, the HEWD underreamer was deactivated and the RHE underreamer activated, enabling the rathole to be underreamed and subsequently the liner and casing strings run fully to the bottom of the hole.
Advanced dynamic drillstring modeling can simulate downhole drilling conditions, enabling improved prejob planning and thus more efficient drilling operations. Proper design of HEWD and RHE BHAs can help the operator efficiently maximize the quality of LWD data while drilling.
Al-Khaldy, M. D. (Kuwait Oil Company) | AlRashidi, A. (Kuwait Oil Company) | Failakawi, K. Al (Kuwait Oil Company) | Dutta, A. (Kuwait Oil Company) | Ayyad, H. (Schlumberger) | Mansour, O. (Schlumberger) | AlMahdy, M. (Schlumberger) | Jamal, S. (Schlumberger)
In North Kuwait, formation evaluation in horizontal/highly deviated wells typically requires the use of Logging While Drilling (LWD) technology. In this paper, we will discuss how for the first time in Kuwait a state-of-the-art wireline open hole tractor has been successfully used to convey an advanced wireline pressure measurement in a horizontal well. Two wells will be discussed in this paper, the first was a short radius horizontal side track in the tight carbonate formation while the second is highly deviated well across sand/shale layers.
Traditionally in horizontal wells, the pressure measurement is either run on drill pipe or LWD. Moreover, the formation tightness posed another challenge, as stabilized formation pressures can be difficult to achieve. To address the challenge of formation tightness and save rig time, a fast wireline pretest measurement tool allowing dynamic control of the pretest system would be conveyed on wireline using Open Hole tractor. A job simulation was conducted, based on the friction force and tool weight, to ensure the ability of conveying the tractor to the required depth in addition to the ultimate tractor drives number with tandem
Both jobs were successfully executed as per plan. The tool was conveyed smoothly across the tight carbonate reservoir to the target depth of 10,030 ft MD at an average tractoring speed of 1800 ft/hr. The job was concluded with a cumulative tractoring footage of 3200 ft and an operating time of 12.5 hours, which resulted in more than 30 hours of rig time savings compared to other alternatives. The requested pressure program was achieved. Due to the pressure tool's low rate pretest capability, in addition to the flexible volume and pretest time options; stabilized formation pressure data could be acquired
The combination of the advanced pressure measurement with a state-of-the-art open hole tractor
An essential element for business success is to secure the best quality services from external providers at the lowest possible cost, which is a challenge not only for operating companies but also for service providers. This challenge is becoming more important for D&WO business, which is a major services consumer. NOCs strive to create a competitive and fair environment to encourage long-term business partnerships with service providers through a transparent process to assign more than 13 D&WO services.
A new process put into practice in the last 2 years, objectively evaluates service providers based on measurable criteria that include the pricing schema, historical performance, HSE compliance, and nationalization compliance of all providers against their contractual obligations. To assure the integrity of the process, an application was developed to fully automate the process, starting with the collection of data from its original sources to evaluate the service providers, through the electronic approval of the final assignment by management.
The application, Automated Services Assignment System (ASAS), provides different functionalities that allow seamless integration of different data sources like performance data from drilling rig morning reports and rig activity scheduling from a corporate database. It evaluates and ranks service providers automatically and provides an automated workflow for approving the services assignment based on a hybrid business model (standard process, service packaging, or lump sum turnkey), and allowing the adoption of additional business requirements during the execution phase through automated change request functionality.
The process and the application enabled D&WO organizations to respond to dynamic changes in their business by running as many scenarios as needed to identify the best business approach, with potential cost savings up to 15 percent (initial rough estimate). Effective management of the process delivers time savings up to 40 percent, compared to the manual process.
Implementing multidimensional evaluation criteria strengthens the credibility and integrity of the process compared to evaluations done based upon single criterion, such as cost or performance. In addition, this automated system combines three different business models seamlessly; capitalizes on corporate official records for drilling operations, HSE, and rig schedule; and enforces comprehensive business rules.
A new concept "local down-hole tubular model", which provides a more sophisticated description of tubular string deflection from local perspective, is proposed to overcome the shortcomings of the conventional integral model. The coupling effects of three factors including wellbore configuration, buckling mode and connector are studied in the local model. Firstly, an equivalent beam-column model is proposed to reduce arbitrary wellbores except vertical wellbores into horizontal wellbores. Thus, the tubular behaviors in arbitrary wellbores can be simplified into that in vertical and horizontal wellbores. Secondly, the two-dimensional (2D) lateral deflection, three-dimensional (3D) inter-helical buckling and intra-helical buckling of tubular strings with and without connectors under four contact cases, namely no contact, point contact, wrap contact and full contact, constrained in horizontal and vertical wellbores are studied. Meanwhile, the fitting formulae which depict the effects of connectors on critical buckling loads, contact forces and bending moments are calculated. At last, the integral model is further amended based on the results from the local model. The results show that the effect of wellbore configuration can be equivalent to additional tubular string weight. Connector parameters are closely related to buckling modes, critical buckling loads, post-buckling deflection curves, bending moments, contact forces, etc. The combination of integral and local models, namely the amended integral model, establishes a more sophisticated description of axial force, torque, bending moment, contact force and buckling mode distributions along the entire tubular string.
Bataee, Mahmood (Universiti Teknologi PETRONAS UTP) | Irawan, Sonny (Universiti Teknologi PETRONAS UTP) | Ridha, Syahrir (Universiti Teknologi PETRONAS UTP) | Hematpour, Hamed (Universiti Teknologi PETRONAS UTP) | Hamdi, Zakaria (Universiti Teknologi PETRONAS UTP)
Enhanced Oil Recovery (EOR) injection methods are increasingly applied globally as the effective method in oil wells. Fluid injection alters the formation stress around the wellbore. In this study an iterative coupling method is proposed to evaluate wellbore stresses for one cycle of water alternating gas (WAG) injection. The effective parameters such as pressures, temperature, saturations and stresses are obtained for the multiphase flow condition using mathematical modeling. In this study, finite difference method is used to calculate pressure, temperature and saturations; and finite volume method is applied to evaluate stresses. Iterative coupling method is used to improve the accuracy of the results. The results show the pressure is boosted around wellbore after injection and how the water bank is pushed by injected gas. Maximum value of radial stress is obtained in the direction of horizontal maximum in-situ stress. Maximum value of tangential stress is determined in the direction of horizontal minimum in-situ stress. Vertical stress around the wellbore is not related to horizontal maximum and minimum in-situ stresses. The shear stress values are small in comparison with other stress types. The accuracy of model results are increased by iterative coupling, which the maximum correction is about 20 psi (0.14 MPa) for pressure. The developed model is capable to be applied in the wellbore to ensure stability for different injection or production cases.
Liwei, Wang (Research Institute of Petroleum E&D(RIPED)-Lang fang Branch, PetroChina) | Bo, Cai (Research Institute of Petroleum E&D(RIPED)-Lang fang Branch, PetroChina) | Xiaohui, Qiu (Research Institute of Petroleum E&D(RIPED)-Lang fang Branch, PetroChina) | Yongjun, Lu (Research Institute of Petroleum E&D(RIPED)-Lang fang Branch, PetroChina) | Wen, Zhai (Research Institute of Petroleum E&D(RIPED)-Lang fang Branch, PetroChina)
In this paper, we will introduce the performances, research's process and a case study of ultra-high temperature fracturing fluid. The ultra-high temperature well is a carbonate formation with 205°C, located in HuaBei Oilfield, East China. The temperature of NiuDong carbonate formation is more than 200°C in HuaBei Oilfield in East China, acid-fracturing is an important stimulation for NiuDong reservoir. As known, the guar fracturing fluid is usually used less than 177°C because of guar molecule's performances, so we develop a ultra-high temperature polymer as pad fluid of acid-fracturing to stimulate the NiuDong carbonate, the polymer is a novel structural terpolymers which can be cross-linked by crosslinking agent and broken by APS. The structure of thickener is a key factor to increase the high temperature resistance of polymer, so a novel molecular structural polymer with C-C bond backbones and C=C bond monomers is developed for the ultra-high temperature fluid, and the hydration group with C-C, C-S, C-N is also added in the side chains with the purpose of decreasing the dissolution time of the polymer. An organic zirconium crosslinking agent with amide groups is selected to crosslink the polymer fluid, and the cross-linking time is controlled. After cross-linked, the network structures of gel fluid like the uniformed petals in the scanning electron microscope, so the viscosity is very high. Under the conditions of 200°C, 170s-1 and shearing120 minutes, the residual viscosity is more than 130mPa.s, The evaluated tests show that carrying proppant of polymer fluid are good, low interfacial tension and low residues. The ultra-high temperature polymer fracturing fluid has been successful used in a Well of NiuDong sag. Ultra-high temperature polymer fracturing fluid provides a selection for the formation with more than 200°C.