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The implementation of multilateral wells in Saudi Aramco, and in the southern area of Ghawar field in particular, is being increased for production and cost optimization. Accessing and stimulating individual laterals is a challenge that requires an optimum design in terms of cost, application and efficiency. This paper will describe a unique utilization of a combined high energy rotary-jetting tool with a multilateral tool (MLT) to access and treat a dual-lateral oil producer in the southern part of Ghawar field. The main purpose of utilizing this combined tool was to acid wash the Arab-D horizontal section of both laterals with nitrified hydrochloric acid using coiled tubing (CT). The objectives of the treatment were to increase flowing bottom-hole pressure (FBHP), remove formation damage and return the well to production. The rotary-jetting tool is a high energy jetting tool that maximizes performance of treatment fluids while minimizing the need for large acid volumes. It can be run with the MLT to enable accessing and stimulating both laterals in a single trip. The implementation of the combined tool resulted in accessing and stimulating both laterals successfully. The well was returned to production at a rate of 11,000 barrels of oil per day (BOPD). The volume of acid was reduced due to utilizing the rotary-jetting tool, which maximized fluid treatment performance. This paper will cover the whole cycle of candidate selection, job design, execution, post job evaluation and conclusion. Introduction Oil drilling strategy in the world as a whole, and Saudi Arabia in particular, has shifted drastically from drilling vertical wells to drilling horizontal and multilateral wells. This increasing trend is a result of enhanced productivity provided by maximizing reservoir contact. These wells have proven successful and economical for field development in oil and gas fields. Although drilling practices and experiences have drastically progressed, there are still limitations on the accessibility of the laterals for treatment or logging. During the past few years, there was a considerable advance in rigless re-entry techniques. The well intervention work can now be conducted on an individual lateral as a result of utilizing the MLT re-entry tool with CT pipe1, 2 & 3.

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With the increasing complexity of well completion, the rigless intervention work is becoming more challenging. Conventional techniques are no more adequate to access long horizontal wells to perform intervention work such as acid stimulation, logging, and zonal isolation. This paper will describe the process of using a downhole coiled tubing (CT) tractor to access a horizontal open hole (OH) extended reach power water injector (PWI) well in the Ghawar field, the world's largest oil field, to perform a huge matrix acid stimulation job. The volume of the treatment is considered one of the largest for a PWI and the first utilization of a CT tractor in the Ghawar field. The paper will review the process of candidate selection, job design and planning, execution, and results and post job evaluation. The job set an excellent example of advancement in intervention technique accessing long horizontal wells beyond the normal reach of coiled tubing. In this job, the CT tractor has increased the reach of CT by 54% and a world record of coiled tubing tractored interval in horizontal OH of more than 5,000 ft was achieved. The injection rate of the stimulated wells was increased by more than twofold. Introduction The giant Ghawar field, located in the Eastern Region of Saudi Arabia, is more than 200 km long and 40 km wide of carbonate reservoir with continuous oil column, Fig. 1. The production from the field was started in 1951 from the northern part and thereafter the field was developed toward the southern tip with the last increment put on stream in 20061. Reservoir characterizations change along the north-south lateral with the southern part known for lower reservoir quality dominated by low permeability fractured formation. To maximize recovery of oil from this unique reservoir, peripheral water injection was started in 19662. As the development reached the southern part of the Ghawar, the reservoir quality dictated the necessity to utilize the latest advancement in drilling technology including long horizontal, maximum reservoir contact (MRC), real-time geosteering, and I-Field initiatives. These complex completion wells present a challenge to production engineers to riglessly access them in order to perform intervention work to enhance performance or remedy downhole problems. Due to tightness of reservoir formation combined with formation damage, matrix acid stimulation jobs were deemed necessary to improve injectivity supporting the reservoir pressure in this part of the field. In extended reach horizontal wells, bullheading of treatment fluid is not efficient due to the nature of this fractured reservoir and a coiled tubing unit (CTU) should be used to provide uniform distribution of the acid across the horizontal treatment interval. Field experience indicated that accessibility of a CTU in horizontal wells is limited due to increased friction generated when the pipe starts to get helically buckled and finally reaches a lockup point where the total down acting forces are no more sufficient to move the CT pipe further in the well. This limits the capability to distribute the treatment across the horizontal section. Different techniques have been used to overcome this limitation of CT to perform intervention work such as using large outside diameter (OD) coiled tubing, downhole vibration tools, and friction reducer chemicals3, 5. Well Completion and History The well was drilled and completed as an extended reach horizontal OH PWI to a total depth (TD) of 17,716 ft and true vertical depth (TVD) of 7,690 ft, Fig. 2. The 6 1/8" OH was drilled from 8,322 ft to TD. The well was completed with 7" completion packer and a tail pipe assembly at 7,358 ft with the end of the tail pipe at 8,794 ft, leaving 8,922 ft of horizontally exposed reservoir formation with a maximum inclination angle of 93°. The average reservoir porosity is 10%. The objective of this completion is to cover the anhydrite formation in the 6 1/8" OH below the 7" liner to the top of the injection formation, Fig. 3. The decision to set the packer was taken during the drilling course due to unexpected formation development and dipping where the setting of the 7" liner was found above the injection formation leaving the anhydrite formation exposed.

Energy conservation is a key aspect to reduce high power consumption in a Gas Oil Separation Plant (GOSP) where oil is separated from water and gas, then shipped. Saudi Aramco is putting a lot of effort into producing large fields, such as the oil field at optimized energy consumption; especially in the summer time, which is always a high demand peak period for power.A swing line network has been constructed between major field plants to provide flexibility for meeting required production targets by reallocating oil production and reduce energy consumption. The swing lines were designed and constructed in late 2005. Presently, they are in use and emerged as a proven tool to lower operating expenditure (OPEX) for plants. This has not only reduced the cost of power but also minimized the environmental impact to some extent by reducing CO 2 emissions.Also, as part of the field production strategy, several oil producers with high water cut were shut-in adding a very remarkable power consumption reduction at their respective plants. This reduction in water production was reached by shutting some of the disposal pumps and/or deferral of forecasted upgrading of the disposal systems. It's worth mentioning that the shut-in of such marginal producers is not solely meant to reduce energy consumption, it's a part of the reservoir production strategy. This paper will focus on energy conservation opportunities that have been realized by utilizing swing lines and controlled water production strategy in part of the oil field.