Background
Over the past two decades Geomechanics has made substantial contributions to the petroleum industry in the following areas:○reducing well construction costs1,○maximizing production2, and○increasing the life of the well.
Currently the industry is venturing into more complex extended reach wells3, deeper water, higher pressure higher temperature environments, sub-salt settings4, lower pore pressure/fracture gradient margins, depleted zones5, fractured carbonates2 and fractured reservoirs6, environmentally sensitive areas, and many other difficult to develop situations, as illustrated in Figure 1.
Geomechanics will play a significant role in addressing these added challenges. The high price of oil is here for a long time. Our technical responsibility is to make sure that the unit development cost (UDC) to produce this oil is contained and subsequently lowered with aggressive application of relevant technology and a knowledgable workforce adept at applying this technology.
Being prepared to deal with the following issues will be integral to success:○borehole (in)stability7–12,○lost circulation13,14,○stuck pipe15,○sand production16,17,○casing collapse18,19,○well failures20,○formation damage21,○sub-salt related issues2.
Each of these problems can strike at any time if we are not vigilant and pro active in avoiding them. Prevention at the outset is more cost-effective than fixing these issues later. I propose we have to bridge the gap between people and technology to be effective in this age of oil industry geomechanics. See Figure 2.
Controlling Costs
Geomechanics-related issues cost the industry billions of dollars.22
We cannot afford, as an industry, to lose billions of dollars on Geomechanics-related non-productive time (NPT) and associated loss in revenues.32
Over the past decade, for the drilling industry on an average twenty two percent of the drilling budget can be attributed to wellbore related NPT. Fifty percent of this NPT is associated with geomechanics related (i.e. wellbore stability, Lost circulation, stuck pipe, etc.) issues.1, 8, 11, 22, 32
In spite of advances in technology, this NPT percentage associated with borehole related problems has not drastically changed over the past decade. NPT percentage of the total drilling budget is much too high and must be lowered to a more acceptable level.
Also further scrutiny of the NPT data suggests a trend, that approximately 90% of costs can be attributed to a small percentage of wells that are highly complex. When these wells have problems, the cost escalates. See Figure 3. Hence, it is critical to manage the available geomechanics resources in the most optimal manner. It is important to identify the high mechanical-risk index wells and get the right geomechanics resources committed - both personnel and data collection - early in the planning stages of the well construction and utilize these resources throughout the well delivery cycle.
