Rami A. Kamal1, Ali M. Al-Shahri1
(1) Saudi Arabian Oil Company, Dhahran, Saudi Arabia
ABSTRACT: Giant Achievements by a Giant Producer; the Saudi Aramco Success Story with Horizontal Drilling
Horizontal drilling is an integral part of the development of the Arab D reservoir (Jurassic) in Ghawar Field. The horizontals are evenly split between producers and injectors. Horizontal drilling was in response to maturation of parts of the field and to uneven waterflooding due to super permeability in some areas, and low sweep, in others. Nearly two thirds of horizontals were new wells, the remainder re-entries. Horizontal completions have included multilaterals, "U" shapes and lateral high angle turns.
Horizontal wells in areas of low permeability resulted in a greater than twofold increase in productivity. Recovery in a complex tar-infested area also resulted in phenomenal success. Mining remnant thin oil columns in water swept zones has recovered millions of barrels of oil.
Horizontal drilling has allowed for better reservoir characterization. Borehole images in these wells provide direct input to 3D fracture network modeling. Field tests and horizontal drilling performance indicate that profit maximization is possible when trajectories are designed to account for fracture trends.
The program has also improved simulation models, by characterizing flow features through field testing techniques. One horizontal well with an 'L' shape provided the full benefit of characterizing the fracture network in the same location instead of drilling different laterals at different locations.
Dynamic field-testing is necessary to optimize the laterals by identifying the nature and extent of the barriers that play important roles in retarding recovery.
Short radius completions on existing vertical wells with dolomitic super k commonly encountered loss circulation in the horizontal section, and led to a redirection of development drilling.
AAPG Search and Discovery Article #90906©2001 AAPG Annual Convention, Denver, Colorado