Drilling used to be hit or miss. In the energy industry’s early days, operators hammered cable tools into the earth, hoping to find crude oil or natural gas. But development of more sophisticated tools has enabled drillers to probe greater depths with more success in less time. Since the remaining hydrocarbons are more difficult to access, the search for oil and gas is constantly leading us into deeper waters and more remote terrain. Drilling and completions technologies have improved dramatically in recent years, enabling Chevron’s portfolio growth.
Until the 1970s, rotary drilling was the dominant technique used in vertical wells. However, these wells were not enough to tap the full potential of reservoirs. Horizontal drilling, enabled by steerable tools, was developed to better access areas of reservoirs that were previously unreachable, thereby increasing production. More recently, the same concept has been pushed further with great results: Directional and extended-reach drilling have allowed operators to access reservoirs far from the drilling location.
Completions technology also has evolved: Installations are done in less time and reliably produce at greater rates. Cased-hole completion involves perforating the well casing and formation so that oil or gas can flow into production tubing. Open-hole completions are another option: Formations with weak rock often require sand screens and gravel packs to be inserted into the reservoir to stabilize the hole and maintain the flow of oil from the reservoir into the well bore. This process controls the migration of sand to avoid well failures and lost production.
Next, acids and other fluids can be pumped into the well under high pressure to fracture, clean and stimulate the rock to increase our ability to produce oil or gas. Finally, production tubing is added to provide an efficient and safe flow to the surface.
What Chevron Is Doing
Chevron’s long-term exploration and development strategy—which blends disciplined, data-driven decision making with superior technical competency—is paying off.
- In Kazakhstan, our Tengizchevroil joint venture uses closed-hole circulating drilling to manage pressure at the Tengiz Field, the world’s deepest operating carbonate oil field. Fit-for-purpose casing design was introduced at Tengiz in 2012. The new casings are smaller, which improves overall drilling efficiency without compromising well integrity.
- In the Gulf of Thailand, where Chevron drills more than 300 wells per year, our “well factory” approach enables maximum efficiency with the minimum capital investment. All of the wells are developed using the same processes, practices and design. The performance of these wells helps make us Thailand’s top crude oil and natural gas producer.
- Chevron recently deployed a new completion system that can save significant time and cost in deepwater developments. The system was installed in the Jack/St. Malo project in the Gulf of Mexico in 2012 and enables the stimulation and gravel pack of multiple production zones in a single trip. Deploying in a single run allows more of the reservoir to be stimulated in less time, which increases efficiency, reliability and production. This technology’s success may lead to its use in other deepwater projects, which could result in additional cost savings and improved completion efficiency.
- An aggressive horizontal drilling campaign at California’s Kern River Field has improved production at this century-old heavy oil field. At depths as shallow as 300 feet, the horizontal wells are drilled with steerable tools to overcome challenges posed by the softness of the surrounding earth. Horizontal drilling has slowed the field’s production decline in a way its vertical wells could not.
Investing in New Finds
Chevron continues to be one of the world’s more active offshore operators. Key exploration areas are the U.S. Gulf of Mexico, the deep waters off western Africa and offshore northwest Australia. Drilling and seismic activities occurred or were in various stages of planning in several other areas, including Argentina, the east coast of Canada, China, Eastern Europe, Indonesia, the Kurdistan region of Iraq, Liberia, Norway, Thailand, Vietnam and offshore the United Kingdom.
In addition to preparing new oil and gas wells for production, drilling teams also revitalize existing wells. This process involves repairing or stimulating the well—such as replacing the tubing or deepening the well—to restore or enhance its production of oil or gas.
Continued investment in drilling and completions technologies is important as wells become deeper, longer and more geometrically complex and as we extract resources from challenging rock formations.
Updated: March 2015