Successful Deployment of Horizontal Openhole Gravel Pack with Alternate Path Technique and Filter-Cake Breaker Placement for Effective Well Cleanup Offshore Myanmar

摘要

The Badamyar project is an offshore gas field located 220 km south of Yangon in the Republic of the Union of Myanmar. In February 2017, four gas wells were successfully drilled and completed using horizontal openhole gravel packing in the Badamyar gas field. The downhole completion design adopted was an alternate path technique using filter-cake breaker deployment for effective well cleanup. Initial geomechanical studies performed in the field show that the sands have low mechanical strength; consequently, they are unconsolidated. This was verified with sonic measurement of 120 us/ft (more than 110 us/ft). An active sand control technique was deemed necessary to ensure a robust well completion with longevity for expected gas production. Based on the comparative risk analysis conducted by the operator for various types of sand control and reservoir drainage, a horizontal openhole gravel pack method was selected to complete the four wells. During the well planning stage, the following specific challenges were identified for the installation of the lower completion: 1. Openhole gravel placement method; alpha/beta wave vs. alternate path technique considering low fracture gradient to achieve 100% pack efficiency; 2. Efficient gravel pack carrier fluid for the selected method; 3. Expected long drain hole in a clay sensitive environment; 4. Effective filter-cake cleanup post-gravel pack; 5. Very fine, poorly consolidated, and immature shaly sands. Downhole sand control equipment deployment, gravel pack placement, filter-cake removal, and initial production results have proven the selected gravel pack method to be successful in the Badamyar field. This paper presents the measures taken to address the project challenges during the design and execution phase and the results achieved. The success achieved can be adopted for the completion of high-rate gas wells with similar reservoir conditions in this area and beyond.