The first installation of intelligent tracers system in extended reach horizontal well was deployed by LUKOIL-Nizhnevolzhskneft LLC in a thin oil rim reservoir with a large gas cap located in the North region of the Caspian sea. Putting in operation of the Yu. Korchagin field is challenging serious tasks during development:relative zone inflow estimation;identifying intervals of water breakthrough;long-term monitoring of oil extraction and water level;monitoring of completion equipment functionality. Traditional technologies of production logging, considering complex well trajectory, are highly risky and expensive. Fiber-optic system of monitoring of Distributed Temperature Sensors (DTS) would be an ideal instrument identifying the source of gas breakthrough, but such technology is not always feasible due to necessity of rotation of the completion during its running in extended reach horizontal well. Performance of periodic field research via cable is limited due to drilling operations on the platform. In addition to perform such survey it is required to use downhole tractors to transport logging tool. Practice of tractors usage in extended horizontal wells in the field has a negative statistics to reach the toe of the well, as for a project operator it's important to verify remote flow contribution (e.g. 7000 m) in total well flow rate. To solve the above problem a relatively new monitoring technology has been applied. At stage of equipment fabrication downhole intelligent chemical sensors were installed in sand screens. Sensors are placed in the drainage area in different intervals along the well to meet objectives by the engineers of LUKOIL Nizhnevolzhskneft LLC to provide flow profiles, identify the location of gas breakthrough and confirmation of the functional work of AICD in the course of time. After selection of surface samples of hydrocarbons at the wellhead, a laboratory analysis is conducted for chemical tracers in the sample and interpretation of tracer signals during unsteady and steady state production is performed. Some period has passed related to operation of the well after its start. The first well equipped with intelligent chemical indicators has its history of production; the well performance can be evaluated both in whole, and for each zone equipped with chemical indicators. This paper will review the experience of wireless monitoring for extend horizontal well on the shelf of the Caspian sea.

The first extended reach horizontal well installed with autonomous ICD (AICD) technology has been deployed by Lukoil in a heterogeneous thin oil rim reservoir with a large gas cap located in the North region of the Caspian sea. The Yuri Korchagin field development has been challenging for geosteering to remain in the thin net pay, for the completion engineers to get planned tallies to TD, for reservoir engineers to minimize risk of rapid increase in GOR after several days of production. To address the later challenge, passive ICD's (PICD) have been trialled with limited success to mitigate gas production from the overlying gas cap and therefore an AICD lower completion was specifically chosen to delay and mitigate gas coning. The gas sensitive completion component reacts to viscosity differences between fluids, essentially choking the more mobile gas autonomously by reducing the flow area due to higher gas production in the local vicinity of where gas breakthrough is occurring. AICDs have been run by other operators and the success criteria has seen a reduction in GOR relative to other wells installed with PICDs but knowing where the gas breakthrough is occurring and is being choked back could not be identified. Traditional permanent monitoring technology and production logs were considered too risky and costly. Distributed temperature sensing may have been ideal to identify gas breakthrough location but was considered prohibitive due to the need to rotate the completion string to reach TD. Running coil tubing conveyed PLTs periodically required medium term planning to schedule the intervention due to active drilling activity on the platform. Moreover, the need for tractors, often failed to reach the toe of the well where it is most critical to verify flow contributions in typically 7000 mMD extended reach wells. A relatively new monitoring technology was identified, that overcame the mentioned installation and intervention challenges by installing intelligent downhole chemical sensors in the drainage area of the sand screens during the manufacturing phase. The sensors can be placed in discrete locations from heel to toe to meeting the Lukoil monitoring objectives of providing flow profiles, identifying the location of gas breakthrough and if the AICD actually chokes gas over time. By obtaining surface samples, analyzing for unique chemical tracers and interpreting their corresponding tracer signals created by well transients and during steady state production. This paper will discuss the first well installation of its kind in Russia and in the world, to be equipped with integrated autonomous inflow control and monitoring technology with no cables to control flow, nor power to operate the devices.

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