Abstract
Earlier, SPE Technical Paper 193036 introduced the development, testing, qualification and deployment of plugged liner technology in Extended Reach Drilling (ERD) field re-development from artificial islands of a giant offshore field in the United Arab Emirates (UAE). This paper will highlight the excellent well performance of the two pilot wells and other island wells with this technology deployment and the significant impact of this technology on initial production rates as well as reservoir recovery.
Plugged LEL technology utilizes Dissolvable Plugged Nozzle Assemblies (DPNA) for deployment with Limited-Entry-Liner lower completions combined with Remote Close Shoes (RCS). The technology results in about 5 days of rig-time saving in well displacement process in extremely long laterals, switching from the non-aqueous reservoir drilling fluid to an aqueous completion brine, by eliminating the use of a dedicated liner displacement string.
Two pilot wells with extra-long horizontal laterals in the very low permeability region were completed with plugged LEL utilizing (1) 169 DPNA 4-mm in 28 zones isolated by swell-packers and (2) 183 DPNA 4-mm in 24 zones isolated by swell-packers. The distribution and location of the DPNA holes along the liner are designed in-house with ExxonMobil proprietary software.
After successful deployment of the plugged liner in two pilot wells which resulted in significant CAPEX reduction upfront through reduced duration for well construction, the well performance was monitored closely in order to assess the success of the technology application in terms of production and reservoir objective. The production rates from both pilot wells exceeded the expected production rates. Apart from total production rate, the critical component of this technology was to ensure all the dissolvable nozzles that plug the liner have dissolved across the lateral enabling lateral conformance which is key to initial production rate and reservoir recovery. Thus, production logging tool (PLT) was performed and the results indicated that the entire extended production lateral is contributing to flow. Apart from well construction cost savings, this technology also enables enhanced wellbore cleaning and improved filter-cake breaker placement. These enhancements resulted in improved well performance than expected and lateral conformance which maximizes reservoir recovery from horizontal wells. After the success of the first two pilot wells, field-wide deployment of the plugged liner was initiated and several wells have been completed with this technology.
This paper will demonstrate the success of the first global deployment of a novel lower completion technology – plugged nozzles LEL - to maximize production and recovery in ERD wells with very long laterals. Value and impact of this technology will be presented in terms of well performance, reservoir recovery in addition to previously highlighted well construction cost savings.
