In Middle East carbonate reservoirs, power water injector (PWI) wells are typically completed with long openhole laterals. The reservoir contact provides pressure support and enhances sweep efficiency in the low-transmissibility reservoirs. Due to the wells deviation and length, coiled tubing (CT) interventions are required to successfully enter and identify each lateral, as well as to remove formation damage by pumping the matrix stimulation treatment across entire laterals. During such CT interventions, laterals are accessed thanks to a hydraulically operated lateral identification tool (LIT), while the stimulation treatment is pumped through a ball-drop-activated high-pressure jetting nozzle (HPJN). LIT and HPJN are efficiently operated by monitoring downhole pressure values both inside and outside of the bottomhole assembly, in real time thanks to CT fiber-optic telemetry. Those downhole pressure readings further assist in optimizing the pumping rate during the job, while keeping it below the fracturing pressure. Finally, the telemetry provides support for gamma ray (GR) logging, which facilitates depth control and lateral identification. This study features a case history during which the matrix stimulation treatment was conducted in two separate CT runs for both laterals of the well. For the first run, the CT initially entered L-0 following the natural path of the well, whereas L-1 was accessed by activating the LIT. Correct lateral entry was confirmed by matching the acquired GR readings with reference logs. After successfully accessing L-1 and reaching its maximum depth, a ¾-in. ball was dropped to isolate the LIT and activate the HPJN for stimulation. During the second run, as the CT entered L-0, GR monitoring was used to confirm lateral accessibility. The stimulation treatment was pumped after reaching maximum depth and isolating the HPJN. During the stimulation of each lateral, 20% viscoelastic diverting acid was utilized for diverting from high-intake zones and 20% HCl to stimulate damaged/tight zones. This operation illustrates how downhole pressure gauge readings are used to sequentially operate the LIT efficiently and activate the HPJN, as well as to pump the matrix stimulation treatment below the fracturing pressure. Real-time GR readings, meanwhile, are used for depth control and to correctly identify laterals.

As a result of the continuous development of drilling technology, more complex wells can be drilled to overcome reservoir challenges and reach target intervals. Over the last decade, innovative drilling techniques have enabled a significant increase in the number of multilaterals and extended-reach wells; this imposes new challenges regarding well accessibility for rigless intervention techniques, which has driven operators, manufacturing, and service companies to develop innovative strategies for servicing these fields. In Saudi Arabia, one extended-reach power water injector (PWI) well was sidetracked to enhance injectivity. During the sidetrack, it was necessary to drill more than 1,000-psi overbalance due to the presence of high-pressure zones across the horizontal section, which resulted in formation damage on the low-pressure intervals. Based on this situation, a well intervention plan was considered which would use Coiled Tubing (CT) acid stimulation to remove the formation damage especially toward the end of the open-hole horizontal section. This operation involved two particular challenges; the first of which was the CT reach across the open-hole section, especially when CT forces simulation predicted a maximum coverage of 50% of the target zone. The second challenge was implementing the proper jetting tool to be able to function with the combination of the downhole tractor and high rate acid stimulation to ensure penetration across the filter cake and remove formation damage in the entire target zone. In order to make this solution feasible a specially designed downhole tractor was engineered, manufactured and incorporated with a newly designed high pressure jetting tool to be able to have full functionality of the downhole tractor while still performing full high rate stimulation to penetrate the damaged zones. This paper describes the combination of slim tractor and high-pressure jetting tool to conduct an effective acid stimulation job in an extended-reach PWI and have a CT reach of 98% instead of the predicted 50% reach in one of the major carbonate reservoirs in the Saudi Arabia. In addition, this paper provides design methodologies, best practices and industry lessons learnt from the experiences gained in the implementation of multi-purpose tool solution in Saudi Arabia.

Electrical Submersible Pumps (ESPs) are widely deployed means of artificial lift methods as they are versatile and adaptable to various well conditions. However, ESP completions have significant installation and operational costs. This paper will address an in-house developed ESP Operational Excellence (OE) initiative that translated into longer run life, increased reliability, and sustained oil production. The objective of this initiative is to unleash the ESPs’ full potentials, and provide structured approach to measure its performance and sustain improvements. The Operational Excellence model is based on asset management cycle of Plan, Do, Check, and Adjust. Production Engineering Team with the support of Artificial Lift Specialty identified two major focus areas; ESP turnaround, and premature failure, as OE candidates. Each focus area was examined in two parts: 1) review of current performance, and 2) review of processes implementation. The current performance was thoroughly reviewed and immediate actions were incorporated and tracked by Key Performance Indicators (KPIs) and driven by results and improvements. In parallel, review of processes implementation was conducted to fine tune current procedure and enforce Best Practices (BPs). ESP turnaround time was significantly reduced through planning ahead required activities, desings, and equipement. This was achieved by setting agenda and streamlined communication with all concerned orginizations. ESP turnaround was done in 20% less days before OE. With the implementation of OE model, oil production was ensured in timely efficient manner without comprising quality as well HSE. The other focus area is premature failure. Once an ESP is properly designed, installed, and operated, the ESP performance is continuously monitored and maintained. The check part of the OE cycle comes into place when the ESP is confirmed failure. Then, the equipment is thoroughly checked using data collected from Dismantle & Inspection Failure Analysis (DIFA) process, with the aim of enhancing performance and deliverability. Based on the detailed investigation, the factors that affected the pump health are integrated and adjusted for the next ESP application. Through DIFA process management, quality assurance activities were conducted to ensure that lessons learned during operation and maintenance, as well as improvements to existing ESP designs are incorporated in new designs; to continuously improve ESP asset integrity and reliability. Therefore, corrective and preventive actions were implemented to resolve common factors that affect ESP performance, such as downhole electrical components including motors and pumps, seals, well conditions and human error during pump installations. By refining these factors, the ESP performance curve was improved and operational excellence was achieved. The implemented Operational Excellence model has shown its significance in optimizing process details from ESP design until operation, which consequently improved ESP run life, increased reliability and sustained oil production.

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.