Te oil producer wells, in the southern are of Saudi Arabia, are mostly completed as horizontal open hole (OH). Some of these wells are dead or on itermittent production due to high water cut, which is caused mainly by water influx through carbonate fissures or fractures. Multiple water shut off (WSO) jobs using inflatable packers, were performed between 2005 and 2010 but failed during execution because of the packers setting failure in OH. The WSO candidate selection process starts with reservoir and production data evaluation, then requires a coiled tubing logging run to identify the water source and adjust the required isolating fluids formulation and volume. For the execution, there is a need to control the placement, inflation, injection and disconnect of the inflatable packers in order to ensure successful WSO treatment. This paper describes how the fiber optic enabled coiled tubing (FOECT) system, enabling realtime downhole data measurement, can optimize the WSO treatments design, execution and evaluation, and increase their success rate. For the job design, production logging tools were run with FOECT string to detect the water source, measure the BHT required for the formulation of WSO fluids, obtain a GR log, and get an X-Y OH caliper critical to decide the best setting depth for the inflatable packer and to confirm the required WSO fluids volume. For the job execution, the depth correlation for the packer setting was performed with the fiber optic bottom hole assembly FOBHA-GR. The inflation of the packer and the injection through it were monitored and adjusted realtime with the FOBHA-PTC measurement inside and outside the FOCT string. The confirmation of the packer setting and the release from it were confirmed with the world's first applications of FOBHA-Tension/Compression sub. Recent production results showed previously dead well flowed at significant oil rate with 10% water cut after performing a WSO with FOECT innovative solution. The integrated FOECT solution, eliminating engineering assumptions during the full cycle of design-execution-evaluation, is a proven WSO technique in OH, which can bring many wells back to economical production.

Scale buildup due to water production can choke oil production and require repetitive scale treatments across entire fields. In subsea wells, the common solution employs a deepwater rig to conduct either workover operations or large-volume scale inhibitor squeezes. Less frequently, coiled tubing (CT) is used from a moonpool vessel. However, current oil prices required a custom solution for subsea well treatments that was more cost effective than either a rig or a moonpool vessel. Similar previous operations successfully used 1 ¾-in. and 2-in. (44.4 mm. and 50 mm.) CT at the same time from a moonpool vessel. A remotely operated vehicle (ROV) in the open water connected the CT to the subsea safety module (SSM) through a dynamic conduit and connected the SSM to the wellhead. An engineered solution to change to 2 7/8-in. CT and use high-rate stimulation pumps was planned to deliver subsea treatments at up to 15 bbl/min. The equipment layout was designed for a multipurpose supply vessel with chemical storage tanks; to increase the available selection of vessels, the CT was designed to run overboard rather than through a moonpool. This project was initiated after accelerated scale buildup occurred because of a pressure decrease close to the bubble point, which happened when the drawdown was increased for aggressive production targets. To effectively inhibit scale in this environment, treatments required thousands of barrels of inhibitor. For wells with more-severe scale conditions, acid treatments were planned. These treatments were delivered with one complete CT package, stimulation pumping fleet, and subsea equipment, which were all installed on the spare deck space of the available vessel. A custom overboard CT deployment tower was designed. The new tower improved the dynamic bend stiffener (DBS) placement, which allowed the clump weights to be deployed with the bottomhole assembly (BHA) and simplified the rig-up. The chosen vessel worked well for the operation; however, the equipment layout and the local weather conditions combined with the response amplitude operator (RAO) of the vessel shortened the projected fatigue life of the CT. CT integrity monitoring with magnetic flux leakage (MFL) measurement was introduced here, and the vessel’s motion reference unit (MRU) provided an input to a fatigue calculator, based on the global riser analysis (GRA). The measurements and the analysis were utilized successfully to prevent CT pipe failures in the open water and deliver the required well treatments. To allow further improvements in deepwater operations, the new engineering work-flow was carefully documented.

The coiled tubing (CT) e-line system is ideal to perform real time production logging (PL) in long horizontal wells, however, the wireline cable inside the CT can restrict the pump rate while the large volumes of acid normally pumped could potentially damage the CT pipe's integrity. Furthermore, using two different CT strings, one for pumping acid and another for performing the PL in real time is neither practical nor economical. A common approach is to use a memory PL tool (PLT), with the associated drawback of recording poor quality data or eventual misruns.To overcome these challenges, a new CT multipurpose system has been developed, allowing real time PL and conventional applications. Leveraging on the telemetry offered by the fiber optic enabled CT (FOECT), already used for downhole measurements while treating in the M field; the new downhole assembly enables the use of standard PLTs in real time mode. At the surface, the converted optical signal is transmitted wirelessly to the PL engineer's portable computer; eliminating the need for conventional acquisition equipment and personnel.In a world first application, the system was used in a land water injection well, after the stimulation job; obtaining the injection profile log with the same quality measurements as a conventional wireline conveyed log. Moreover, the data demonstrated a uniform injection profile. Additional field applications are also briefly discussed in this paper.The new multipurpose FOECT reduces the mobilization and logistics otherwise required, as well as the time and cost compared to existing alternatives. This new capability can be extended to other scenarios like offshore or remote environments, where operational costs have a larger impact. Ultimately, the system opens the door for performing diagnosis, treatment and evaluation in a single well intervention mobilization; making CT operations more efficient and providing more data for production engineers.

Multiphase production logging is essential to identify the contribution of different zones, types of fluids produced and other production related issues in producing wells. Data collected is used to determine if the well requires other services to enhance production or isolate unwanted zones.Locating water production and cross flow between thief zones are common problems for carbonate formations. Remedial well services require costly multiple mobilizations of wireline, coiled tubing (CT) and stimulation units. Results might not be accurate due to the time gap between identifying the problem and implementing the action.The new fiber optic enabled coiled tubing (FOECT) system supports many well intervention services, such as production logging, water shut-offs and/or acid stimulations with a single CT string. Combining FOECT with a real-time multiphase production logging tool (MPLT) reduces well downtime and improves remedial service quality control. Downtime is reduced by using the same surface equipment of FOECT to perform multiphase logging and also remedial work. Only the required bottom-hole assembly (BHA) needs to be changed. This successful logging job for Saudi Aramco allows evaluating remedial well services to be planned right after the production logging job to maximize quality control. This paper documents the implementation of the FOECT system with real-time MPLTs and demonstrates the following improvements for the Ghawar field: 1. First time in a Saudi FOECT system and MPLTs were used to log a wet oil producer well for immediate evaluation of remedial work needed. 2. Significant reduction of well downtime by eliminating multiple mobilizations of wireline, CT and pumping units. 3. Established best practices for production logging with FOECT and multiphase tools, including equipment rig up and single acquisition system setup. 4. Optimize the required equipment by eliminating the electric line (e-line) logging unit.

In the past, the operational and cost concerns of being able to treat and evaluate multilateral wells have left operators with limited economical options for remediation and evaluation. This paper describes a combination of fiber optic-enabled measurement system and a selective multilateral reentry tool.The new system's bottomhole assembly design includes a multilateral reentry tool and real-time bottom hole feedback. The live feedback provides the operator with constant tool position in the wellbore which can serve as a key indicator of downhole tool function. With these specific measurements, downhole CT operations can be tracked and analyzed more quickly and clearly than ever before. Furthermore, this constant stream of critical data arms the onsite engineers and operators with information to make immediate decisions and thereby increase overall intervention efficiencies. This paper demonstrates how this system has been effectively used during stimulation services for openhole multi lateral wells in Canada.