Old – this is typically the word used to define a mature oil and gas field. Webster’s dictionary defines the term ‘old’ as persisting from an earlier time or long standing. At Halliburton however, our definition of a mature field is not defined by age but rather by where the field is with respect to its peak production. In other words, a mature field is one where production has reached its peak and has started to decline.
The graph below is a production curve over time for an actual field in Canada. The y-axis represents the daily production level. You can see that production started in the mid 1950s and steadily increased until it hit its peak in 1968. At this point, production started to decline and moved this field into the category of a mature field.
This drop in production, or the right hand side of the curve, is called the decline curve. It is the slope of this decline curve that we want to flatten, extend, or reverse through our secondary, improved, and/or enhanced recovery efforts. Secondary, improved, and enhanced recovery efforts bring increases in a mature field’s production. We can choose to use advanced petrochemical techniques to assist declining wells with skin damage or other issues to help sustain production, or we can support the drive mechanism by using water injection wells to help push hydrocarbons out of the ground. Another approach might be to drill multilaterals to improve reservoir drainage or inject steam, Co2, or microbial enhanced oil recovery in order to keep the field alive. The point I’m trying to make here is that numerous methodologies, techniques, and technologies exist to help extend the life of mature fields.
At Halliburton, we are successfully challenging the conventional thinking that improved and enhanced recovery activities are too costly and ineffective to be justified. Our innovative methodologies, new techniques, and technologies are in fact proving that revitalization activities can be cost-effective, while increasing ultimate recovery by an average of 20% or more.
Another aspect you need to understand when talking about mature fields is the concept of economic limit. The fact that we only recover on average 35% of the oil in place globally is not a function of technology or know-how, but rather it is dictated by what is economic to extract. The challenge therefore, is finding and applying technology and know-how that allows us to extract the resources at a cost that achieves the economic threshold.
For the example illustrated in the graph above, excluding any effort to stop the decline curve, one would opt to shut the field in where the decline curve intersects the economic limit…at about 2010.
I liken mature fields to a comment that was made by the famous American actor George Burns:
“You can’t help getting older, but you don’t have to get old.” That is the same way Halliburton looks at mature fields – we bring in the right mix of people and technology to help keep mature fields alive and producing and not ‘old’.