Saudi Aramco’s Gas Reservoir Management Department is driving ahead with its non-associated gas programme. O&G Middle East speaks exclusively to the team charged with helping meet the energy needs of the Kingdom
The Kingdom of Saudi Arabia’s ambitious energy targets are no secret; with a rapidly growing population, the country will have to markedly increase what is already a sizeable output of gas. Natural gas represents a vital source of energy for the Kingdom.
Saudi Arabia’s energy landscape is dominated by Saudi Aramco, the national oil and gas company and one of the largest in the world of hydrocarbon operators. The company is investing heavily in a range of measures to boost the country’s energy output.
As part of that over-arching effort, Saudi Aramco is working to develop its gas resources, with demand set to soar between now and into the next decade. As a result, Saudi Aramco has set a target to significantly increase gas production during the upcoming years.
And crucial to that effort is the energy giant’s Gas Reservoir Management Department (GRMD), which is responsible for the Saudi Aramco’s non-associated gas programme. It boasts more than 700 wells that currently supply and fill the gas plant requirements for the Kingdom.
More than 120 GRMD professionals, in coordination with experts from other organisations, are heavily involved in the effort to develop the Kingdom’s non-associated gas potential.
“GRMD is committed to the Accelerated Transformation Programme (ATP) for the gas programme’s role in identifying additional gas resources and increasing gas supply to help meet the Kingdom’s growing energy demand,” says Adnan Al-Kannan, manager of GRMD, Saudi Aramco, who won the Production Manager of the Year accolade at September’s Oil & Gas Middle East Awards.
“The department continues to steward new technologies within the gas programme to enhance production and increase reserves. They include seismic imaging to identify ‘sweet spots’, long extended reach horizontal wells to improve reservoir contact, and multistage fracture stimulation to enhance production from moderate to tight formations.
“In addition, underbalanced coiled tubing drilling is utilised to stay within and tap into productive layers, and evaluating the feasibility of using low-pressure systems. This significantly decreases field abandonment pressures, thereby increasing production and ultimate gas recovery.
“These technologies are being utilised to produce gas that otherwise would not be recovered using conventional methods. This successful programme will continue and be expanded in certain areas.”
The initiative is proving to be a successful one; the approach of tapping both conventional and tight gas resources in and around existing fields has resulted in the discovery of new reservoirs and adding to potential by extending previous field limits. Deepening selected wells has proven to be an effective and cost-effective method to access previously untapped formations.
To elaborate, the underbalance coiled tubing drilling rigless technology, which has been described as a ‘game changer, for the gas programme, has increased the productivity of tied-in low rate gas producers, with more wells planned without utilising a conventional rig.
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The rigless unit uses slim drilling assemblies to place multi-slim laterals within the reservoir, while flowing the well and transferring the produced gas to the nearest processing facility throughout the drilling operation — eliminating flaring and protecting the environment.
“Over the past five years, many low rate gas wells have been re-drilled with this application that has delivered higher gas rates, reduced drilling time and lowered unit development cost compared to conventional drilling,” comments Mike Haas, Offshore Gas Reservoir Engineering Supervisor, GRMD, Saudi Aramco.
“All these technologies have significantly increased the non-associated gas portfolio. The current yearly addition through the continuation of these methodologies is to reduce production cost effectively to help meet the Kingdom’s increasing energy requirements.”
Even more recently Saudi Aramco made a hugely significant breakthrough when the Karan field — the first offshore non-associated gas field — was put on production. Saudi Aramco developed the Karan gas field, located in one of the busiest oil tanker shipping areas in the world, in record time from exploration to production.
The Karan field was developed in five years after discovery and is Saudi Aramco’s first offshore non-associated gas development that was fast-tracked. The initial start-up wells were drilled from multi-well platforms in moderate water depth and completed with monobore completions to meet the required well production rates. The gas is used for domestic consumption to meet the Kingdom’s energy needs for the foreseeable future.
The success of two new large offshore non-associated gas discoveries has spurred Saudi Aramco’s GRMD department onto further breakthroughs and developments. “The new offshore gas field increments are on track to supply gas to a new ‘grass-roots’ gas plant to be completed in the near future,” says Al-Kanaan.
“The new offshore non-associated gas fields are being developed with big bore completions and high pressure rating for the first time in the world to supply gas for Saudi Arabia. The big bore concept significantly reduced the well count from conventional to the big bore completed wells, thereby saving significant upstream costs, and providing much more production flexibility to meet gas demand.”
Dr. Zillur Rahim, Senior Petroleum Engineer Consultant and Hydraulic Fracturing Team Lead, GRMD, Saudi Aramco, tells Oil & Gas Middle East that hydraulic fracturing in horizontal wells was a major improvement for Saudi Aramco’s gas programme, especially compared to dual lateral and vertical stimulated well methods.
“Application of multi-stage hydraulic fracturing has been very effective in developing moderate to tight carbonate and sandstone reservoirs worldwide. The well potentials and sustainability have significantly increased, supplying an environmental friendly and strong source of energy. Saudi Arabia is at the forefront on application of hydraulic fracturing technology and internationally recognised, contributing to its technical enhancement and deriving immense benefits from its application,” he comments.
“The significant improvement of gas production and transforming low producing areas to commercially viable assets can be mostly attributed to the intense fracturing and stimulation campaign.
Subsequent to the first few stimulation treatments as a startup technology, hydraulic fracturing quickly became very popular due to the benefits derived from such operations. It is now routine practice to enhance production rates in moderate to tight gas reservoirs, in both carbonate and sandstone formations.
“Since its inception, the hydraulic fracturing program in Saudi Aramco has made substantial progress in improving and optimising the conventional practices in both stimulation and completion.
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This includes the testing and use of high-strength proppant, retarded acids, emulsified systems, low polymer non-damaging fluids, advanced open-hole multistage completion assemblies, cased plug and perforation stimulation treatments, and innovative sequential pumping operation.”
As well as advancing fracturing pumping operations, Saudi Aramco’s GRMD team is also working on a number of other improvements. Among them is the real-time geomechanics to ensure drilling wells in the minimum in-situ stress direction, low gel loading and optimal chemical concentration to minimize formation damage yet providing adequate fluid viscosity.
These enhancements create and propagate uniform fractures, ensure high conductivity, and a fast and efficient post-treatment cleanup, thereby increasing retained proppant permeability and gas production.
Simulation modelling is routinely performed to compute the number of optimal transverse fractures needed to achieve desired well production rate, the dimensions of these induced fractures, and fracture conductivity.
The application of real-time geomechanics has enabled drilling horizontal wells in the minimum in-situ stress direction that helps creating multiple, non-communicating, independent hydraulic fractures. What matters in the end, is a damage-free, high conductivity clean fracture and the large reservoir/fracture contact area – which all attribute to enhanced well productivity.
“Use of improved chemical systems for a second cleanup on few already fractured wells that were showing low productivity revived them at a higher sustained rate.
Rigorous modelling with the best available data has enabled the engineers to design and select the optimal completion and stimulation options to attain higher well productivity,” says Danah Alsana, Petroleum Engineer, GRMD
“The use of high strength proppant to encounter in-situ stress has improved sustained fracture conductivity overcoming gel damage, fine migration, embedment, and proppant degradation with time. All of these factors, if not addressed properly, would adversely affect well performance,” she adds.
