Gorgi, Sam (Halliburton) | Joya, Jose Francisco (Halliburton) | Al-Ebrahim, Ahmed (Kuwait Oil Company) | Rashed Al-Othman, Mohamad (Kuwait Oil Company) | Abdullah Al-Dousari, Mohamad (Kuwait Oil Company) | Mohamad Ahmed, Abdulsamad (Kuwait Oil Company) | Omar Hassan, Mohamad (Kuwait Oil Company) | Mohammad Al-Mansour, Jassim (Kuwait Oil Company) | Elsayed, Abdou (Kuwait Oil Company) | Alboueshi, Alaa Eldin (Halliburton) | Allam, Ahmed (Halliburton) | Robles, Fernando (Halliburton)
This paper presents a case history application of real-time fiber-optic technology in the Bahrah oil field, onshore Kuwait. A primary challenge during openhole swellable packer completion operations with multistage fracturing is understanding the number of fractures induced in the formation, particularly in heterogeneous formations where the fracture pressure energy will be distributed along the openhole section. Therefore, fiber-optic technology was selected for the Bahrah project. The application consists in diagnosing a tight carbonate reservoir after multistage acid fracturing and milling the baffles of a production sleeve completion to obtain a well production profile. This technology consists of a fiber-optic cable and a modular sensing bottomhole assembly (BHA). The fiber-optic cable provides distributed temperature sensing (DTS), whereas the BHA is used to monitor pressure, temperature, and the casing collar locator (CCL) in real time.
The usual procedure when using conventional coiled tubing (CT) to stimulate a carbonate openhole section is to treat all pay zones with acid and diverter, which increases both operation time and operational costs. In addition, inadequate control of the treatment placement will often result in ineffective stimulation. When using the fiber-optic technology, monitoring is performed by analyzing the distributed temperature profiles both before and after stimulation; the BHA helps ensure that the optimum pressure is maintained and that the fluid is placed accurately through depth correlation sensors. All components of this intervention are performed in a single trip, which reduces both costs and operation time.
This paper presents an application that uses the modular sensing BHA to improve the performance of milling balls and baffles in the horizontal production sleeve completion. Afterward, DTS is used to diagnose the reservoir performance after multistage acid fracturing to identify fracture initiation points (FIPs). This assists in design optimization, provides better understanding of formation properties, and helps determine the flow rate distribution of each stage across the entire lateral. Another application uses DTS to obtain the production profile of a 3,286-ft horizontal section while flowing back the well through an electrical submersible pump (ESP). The paper presents the methodology and results of these applications.
Using this technology in the petroleum industry helps reduce operation time by up to 50% as a result of performing various CT activities in a single run. This eliminates the need for additional logging or slickline runs using the same BHA, after performing the milling operation to collect DTS data for FIPs and flow rate distribution analysis in the same run. It also reduces costs by enabling real-time decision-making capabilities and effective stimulation.
Jassem, H. (Saudi Aramco) | Al-Shehri, Ayedh M (Saudi Aramco) | Al-Shammari, Nayef S. (Saudi Aramco) | Al-Gamber, S. D. (Saudi Aramco) | Mutairi, K. M. (Saudi Aramco) | Said, R. (Saudi Aramco) | Barkat, S. (Schlumberger) | Ahmed, D. (Schlumberger)
The study well was first drilled as single lateral Power Water Injector (PWI), then sidetracked as a multilateral injector with a total reservoir contact of 23,094 ft. The well was completed with three new laterals all placed up-dip in the water leg. This geometry was specifically intended to increase injection potential and provide more pressure support in the lower transmissibility areas of the well's complex, carbonate field.
This paper discusses the Coiled Tubing (CT) accessibility challenges, technology deployment and lesson learned for stimulating the first quad-lateral extended reach PWI ever drilled in the study area in Saudi Arabia. The PWI is used to increase the injection capacity and provide extra support to reservoir pressure.
Due to the challenging extended reach well trajectory, technology unavailability, challenge of effectively access all 4 laterals and properly identify each later to stimulate them, CT with real time downhole monitoring was used in conjunction with a multi-lateral tool access. The multi-lateral tool (MLT) was used to provide controlled, oriented mapping to access each lateral independently. The indication for the correct lateral was confirmed by both downhole pressure drop across the multi-lateral tool. As all the laterals are extended reach, getting to total depth (TD) was challenging for some of the laterals even after implementing all the reach techniques. In order to be efficient and identify which lateral was accessed an innovative method was developed by using Gamma Ray (GR) tool and casing collar locator (CCL) to properly identify each lateral before having to reach TD to determine the lateral accessed.
Once the proper lateral is accessed and determined, the acid treatment placement was pinpointed to and optimized by distributed temperature survey (DTS), which helped determine in real-time high permeable thief zones and tight or damaged zones. The treatment schedule was designed to divert from high intake zones using viscoelastic surfactant diverting acid system, followed by hydrochloric (HCl) acid for stimulation. The intervention was completed successfully without any safety incidents. The use of GR, CCL and downhole pressure & temperature measurements in conjunction with MLT tool gave the ideal method for lateral access and lateral confirmation especially when reaching to Total Depth (TD) was not feasible due to CT lockup. In addition the use of DTS for optimum stimulation placement was the key in improving operation efficiency.
The methods developed in this paper on how downhole measurements such as pressure inside and outside CT and it's differential, CCL, GR, MLT and DTS can be used in Multilateral wells has proven to be a major success. This first intervention of its kind has opened new innovative ways and techniques of confidently stimulate all the multilateral extended reach wells in Saudi Arabia.
Al Shoaibi, S. (Petroleum Development) | Kechichian, J. (Petroleum Development) | Mjeni, R. (Petroleum Development) | Al Rajhi, S. (Petroleum Development) | Bakker, G. G. (Petroleum Development) | Hemink, G. (Shell Global Solutions International B.V) | Freeman, F. (Shell Global Solutions International B.V)
Fiber Optics Distributed sensing technologies are evolving in the petroleum industry with its potential applicability in many areas of surveillance. Petroleum Development Oman (PDO) is embarking upon the implementation of this technology in various assets including both Gas and Oil fields. The vision of the company is to have the Fiber Optics distributed sensing technology as a surveillance tool in the Well and Reservoir Management (WRFM) toolbox and to become, where appropriate, a key element of its cycle. In comparison to conventional surveillance, fiber optic distributed sensing requires no well intervention and thereby reducing HSSE exposure and production deferment. In addition, the installed fibers can be used for multiple applications, e.g. hydraulic fracture performance monitoring and inflow performance monitoring. Recently, PDO trialed Distributed Acoustic Sensing (DAS) and Distributed Temperature Sensing (DTS) technologies utilizing both, dip-in surveys and permanent installation of fiber optics in the wells.
Fiber optic implementation in PDO included a polymer flooding trial in heavy oil, high permeability clastic reservoir with a strong bottom water aquifer drive. The objective was to monitor well conformance as the polymer injection progressed. The horizontal injectors were completed with pre-drilled liner and divided into four zones, each with an independent Inflow Control Valve (ICV). The well was completed with a multi-mode (MM) fiber pumped into control lines three injectors. Real time DTS data was acquired continuously in all three wells while DAS was acquired as per the injection program in one injector. DAS and DTS data were analyzed to quantify the changes in injection profile and rate in each ICV zone. This provided timely information needed for decisions related to manipulation of the ICV valves to ensure best utilization of the polymer.
Another example of fiber optics was a dip-in survey in a deep gas well with commingled production which covered stacked reservoirs. This was run in order to prove the concept of flow response on DAS/DTS signals in terms of gas flowing and liquid lifting detection. The acoustic signature observed was mainly due to gas entering the well through perforations. This was detected by DAS and DTS and allowed a qualitative inflow profile to be generated. The dip in survey proved the concept and allowed justification for the permanent installation of fiber optics behind casing. The objective of the permanent setup is to improve the sensitivity of the measurement and allow for better quantification of inflow per zone. In this paper, the approach of implementing fiber optic technologies in PDO is discussed with emphasis on value generation in the various assets. Additionally, the examples mentioned in this abstract are discussed in more details and based on the results, the way forward is described.
Abu Roash-D is characterized as a carbonate reservoir in Abu Gharadig field, Western Desert of Egypt. It has a good lateral continuity, contains natural fractures with poor connectivity in addition to formation tightness. To further increase the production from the field, a full development plan for Abu Roash-D carbonate reservoir was initiated with drilling of horizontal wells. The main objectives of drilling such horizontal wells was to develop the tight unconventional reservoirs and increase production by dramatically increasing the contact area with the producing interval, maximizing drainage volume around a well and link the natural fractures network thus, achieving an economically production targets.
The effective placement of sufficient acid volume along the open-hole section of such horizontal wells provides significant challenges in acid diversion due to the high permeability streaks that requires a very effective diversion technique for optimal acid distribution a long the open hole lateral for a successful acid stimulation treatment.
A fiber optic enabled coiled tubing attempts to tackle some of these limitations. This new approach deploys downhole sensors with fiber optic telemetry inside the coiled tubing string provides a real time temperature, pressure and correlated depth measurments. The fiber optic telemetry allows distributed temperature surveys recording for obtaining temperature profiles across the entire wellbore. Monitoring the distributed temperature sensing (DTS) profiles accompined with downhole pressure data interpretation enables real time diagnostic of downhole events between the stimulation stages providing an important aid to further optimize and improve the performance of stimulation treatments.
This paper presents case histories of the first time implementation of horizontal wells in Abu Roash-D tight carbonate reservoir in Egypt's western desert in which fiber optic enabled coiled tubing was utilized to optimize stimulation treatment. The real time monitoring of downhole distributed temperature sensing profiles allowed the identification of both high permeability zones as well as tight zones across the entire openhole lateral. This enabled the operator to take pro-active decision on where to spot diverter or acid, select the best diversion technique and allow for treatment optimization.
Buhassan, Shaker (Saudi Aramco) | Halder, Surajit (Saudi Aramco) | Tammar, Hassan (Saudi Aramco) | Beheiri, Faisal (Saudi Aramco) | Ahmed, Danish (Schlumberger) | Brown, George (Schlumberger) | MacGuidwin, Jeffrey Thomas (Schlumberger) | Haus, Jacques (Schlumberger) | Moscato, Tullio (Schlumberger) | Molero, Nestor (Schlumberger) | Manzanera, Fernando Baez (Schlumberger)
During the last 5 years, one of the most common matrix acidizing enhancement techniques used to improve zonal coverage in open hole or cased hole wells is conducting a distributed temperature survey (DTS) using coiled tubing (CT) equipped with fiberoptic and real-time downhole sensors during the preflush stage before the main stimulation treatment. This is used to identify high and low intake zones so the pumping schedule can be modified to selectively place diverters and acidizing fluids with a high degree of control. Once stimulation treatment has been completed, a final DTS analysis is performed to evaluate the zonal coverage and effectiveness of the diversion. Even though this technique has provided satisfactory results, alternative methods providing faster and more accurate understanding of flow distribution between the zones and laterals are needed, especially if there is limited temperature contrast between fluids and reservoir. Thus, an innovative coiled tubing real-time flow tool has been recently developed to monitor flow direction and fluid velocity. This measurement is based on direct measurement of the heat transfer from the sensors to the surrounding fluid using a calorimetric anemometry principle. The first worldwide use of this technology in a Saudi Aramco injector well showed this to be a viable new approach to downhole flow monitoring that can be used by itself or in conjunction with DTS, depending on the constraints of each individual intervention.
Intelligent Reservoir Management and Monitoring has played a key role in the pursuit of improving the hydrocarbon recovery and reducing the development expenditure in the challenging multi-stacked compartmentalized fields which have proved to be perplexing in a number of ways which include preventing or delaying water breakthrough, extenuating wellbore instability, sand production etc. Reservoir-management and monitoring options have been greatly improved in recent decade by smart completions comprising of downhole monitoring and control equipments like permanent down-hole gauges to have "eyes" into the reservoir and to monitor performance for each zone; dynamic active flow control valves, which aid in equalization of the reservoir inflow into the wellbore; and the SCADA system which enables the real time monitoring and control of the downhole and surface equipment remotely from the control room.
Kabir, Mir Rezaul (Kuwait Oil Company) | AIi, AfzaI (Kuwait OiI Company) | Pradhan, S. P. (Kuwait OiI Company) | Dashti, Qasem (Kuwait OiI Company) | AI-Jasmi, A. K. (Kuwait OiI Company) | Abid, Ridha (Weatherford International)
The scope of the pilot project was to test fiber optic sensor technology in deep High Temperature (HT-HP) reservoirs and evaluate the best available sensors in the market for real time monitoring of down-hole pressure and temperature (P-T) in such an adverse environment. The task team had selected the optical P-T sensors conveyed on fiber optic cable from a qualified vendor after a thorough evaluation, considering the harsh environment of these reservoirs. After selecting the vendor, the fiber optic system was custom designed and installed down-hole in a selected deep HT-HP well in the Raudhatain field of North Kuwait. The system was installed and commissioned in mid February 2011 and has been successfully working to date, providing real-time pressure and temperature data from the reservoir section.
In this project the P-T signals captured by the optical down-hole sensors are transmitted through the fiber optic cable to the Reservoir Monitoring System (RMS) unit at the surface that is connected to the SCADA system. The SCADA system sends the data through Wi-Max to the Digital Data Gathering Centre in the Field Development Gas (FDG) office. The sensors are continuously providing reservoir data at a time interval as frequent as 60 data points per minute. The technology provided by the vendor for this pilot is found to be robust and reliable. The pressure and temperature sensors employed in this pilot have shown impressive resolution and dynamic response capabilities. Based on the results it is concluded that the pilot is successful and the system is recommended for future implementation in deep HT-HP wells of North Kuwait fields.
The project involved manufacturing, shipping and procuring the material from the Far-East and the USA. It also involved modification of well head to accept fiber optic cable entry into the well bore and use of specially designed low solid content packer fluid. The pilot was considered successfully completed after monitoring for 180 days in the month of August -2011.
In Kuwait Oil Company (KOC) this first fiber optic sensor technology pilot was conducted by Research and Technology (R&T) and Field Development Gas (FDG) with the coordination of Deep Drilling and other groups, in a deep HT-HP well with the primary objective to monitor two key reservoir parameters; temperature and pressure. The reservoirs in North Kuwait are complex soil bodies that have a high potential for condensate and gas. The continuous, real time understanding of these reservoirs is vital in order to optimize their exploitation; hence KOC adopted a strategy of deploying fiber optic monitoring systems.
Carbonate acidizing is very common in the oil industry. In the case of mature heterogeneous reservoirs with different permeabilities and high water cut, stimulation in these reservoirs can be a real challenge. Major technology developments in well stimulation over the last few years are evident in numerous publications. Two new technologies currently in the spotlight were applied in a matured Saudi Arabian oil field.
This paper addresses case studies of selective stimulation using a fiber optic enabled coiled tubing (FOECT) system combined with smart chemicals where real-time distributed temperature sensing technology facilitated instant decision process of temporary zonal isolation, fluid placement and treatment efficiency evaluation. The paper also describes another acid stimulation technology used in the same matured field where the completion is equipped with a multistage stimulation completion designed to selectively treat different reservoir sections using a ball drop mechanism. Candidate selection, treatment design, execution, and post job evaluation for both the technologies will be discussed in the paper. Lessons learned and experience gained to optimize similar future jobs will be included in this paper.
Success of matrix stimulation treatments depend on the uniform distribution oftreating fluids over the entire production/injection interval. Thus, when acidis pumped into a well, it naturally flows to the most permeable/least damagedzone. To avoid improper placement of acid into one interval of a zone ofdifferent injectivities, diversion techniques can be applied. Diversion can beaccomplished by either mechanical means or chemical means.
Diverting chemicals are deposited over the perforations or the formation. Whendeposited, they form a layer with a lower permeability than the formation it iscovering. This imposes an additional pressure drop needed to penetrate the cakewill cause the fluid to divert to another part of the perforated interval.Eventually, uniform injection is accomplished across the whole interval.
Different concentrations of diverting agents can be used to get the requireddiversion, but how to know if the diverter pumped is indeed diverting or not isa challenge. Bottom-hole pressure or temperature responses can be checkedduring the job to get an idea if diverter is working properly. Thus, FiberOptic Enabled Coiled Tubing with Fiber Optic Enabled Bottom-hole Assembly(FOEBHA) with pressure and temperature sensors for real-time downholemeasurements and Distributed Temperature Sensing (DTS) is the best solutionavailable.
This paper describes the use of different concentrations of diverter i.e. viscoelastic diverting agent and the behavior responses of downhole parameters withtheir usage.
Copyright 2013, Society of Petroleum Engineers This paper was prepared for presentation at the SPE Middle East Unconventional Gas Conference and Exhibition held in Muscat, Oman, 28-30 January 2013. This paper was selected for presentation by an SPE program committee following review of information contained in an abstract submitted by the author(s). Electronic reproduction, distribution, or storage of any part of this paper without the written consent of the Society of Petroleum Engineers is prohibited. Permission to reproduce in print is restricted to an abstract of not more than 300 words; illustrations may not be copied. The abstract must contain conspicuous acknowledgment of SPE copyright. Abstract Deciding on the optimum spacing between fractures and selecting the optimum fracture treatment parameters is a key challenge in designing the hydraulic fracture stimulations of Unconventional Gas and Liquid Rich Shale (UGLRS) wells. To make those decisions more effectively and more rapidly, (downhole) hydraulic fracture diagnostic tools can be used which provide a better understanding of how and where fractures initiate and what the distribution of fluid and proppant volume is downhole. One emerging technology, fiber optic distributed acoustic sensing (DAS) has the potential of providing such key diagnostic insights during hydraulic fracturing operations in real-time. This paper describes some of the background technology and presents the results of several hydraulic fracture stimulation (HFS) diagnostic case studies. The results illustrate how DAS has been used to perform real-time monitoring for both openhole multistage fracturing and "Cemented Plug & Perf Completions".