Billyjack
Rookie
- Dec 10, 2015
- 27
- 2
- 1
There is constant mindless prattle in the media concerning the practice of hydraulic fracturing in order to produce commercial quantities of oil and gas. Many of the arguments are being made by people with an agenda to create an energy crisis and are therefore specious. I am posting to provide the facts concerning the reason for fracturing and the actual mechanical processes involved that hopefully when one hears the current propaganda being espoused you will have at least a few facts to compare. Having been a practicing petroleum engineer for nearly 40 years, I am qualified to discuss as opposed to the self appointed experts or journalists who had difficulty with middle school algebra much less differential equations.
Hydraulic fracturing is not new technology. The industry has been fracturing wells for over 50 years. The process is expensive and requires extensive design and expertise. The current surge of the practice is primarily because of higher energy prices making the practice more economical in reservoirs that at lower prices were uneconomical. The purpose of fracturing is to increase the rate of production from very low permeability reservoirs. If done properly the process entails making a “crack” in the oil saturated rocks by injecting water that has been turned into “jello” at a rate and pressure beyond the capacity of the porous formation to absorb. This crack is then filled with a “proppant” generally sand that keeps the fracture from closing, thereby creating a flow path to the wellbore. In essence, a properly designed and executed “frac” job will increase the effective diameter of the wellbore from 8 inches to as much as 20 feet. As anyone should be able to imagine you can move a lot more fluid through a pipe with a 20 foot diameter than with an 8 inch diameter.
In order to accomplish this, it is imperative that the fracture be confined to the producing formation and not allowed to go any other places where it will not help the well produce. Why would anyone want to spend a million dollars to fracture a well to increase production and not take the precautions to make sure it went where it will do the most good? In short, the arguments about hydraulic fracturing affecting fresh water horizons as a common practice are not true. Like anywhere with a concentration of horsepower there is always danger. Like the space shuttle that blew up had concentration of 1,000,000+ horsepower. Your car probably has 200 hp and ends up being dangerous and kills 40,000 people a year, but I don’t hear anyone trying to ban cars. Similarly, there are undoubtedly some failures during fracture stimulations. However, when I am personally performing a frac-job and observe a dramatic pressure change indicating the fracture is not going where I want, the job is shut down immediately. From a catastrophic failure to shut down of the job will take less than 30 seconds. Why would I want to spend that much money and not put the fracture in the right place?
The toxic chemicals myth should also be addressed. To begin most hydraulic fracture jobs are composed of 99% water. The primary ingredients we use are polymers that cause the water to form a gel. These polymers are not anymore toxic than any other gelling agent. The rest of the proprietary mixtures are not more excessively toxic than the chemicals under your sink. These mixtures are generally pumped inside at least two and as many as four high strength steel casings that are cemented concentrically in the hole. Whether we are going to fracture or not a “surface casing” string is always run and cemented to a depth to protect any freshwater aquifers from contamination during the drilling and production phase of an oil well. Since the formations that produce oil may be a mile or more underground and the fresh water aquifers seldom exists below 1000’ from the surface it is highly unlikely to be able to fracture into any freshwater outside the casing protection. It is physically impossible to make a fracture grow in height much more than 1000’ and that would be a poor fracture design. So therefore how can one expect a fracture fluid to get into fresh water except in very unusual circumstances caused by a mechanical failure through at least 2 strings of high strength steel pipe which will be easily observable by a dramatic change in surface treating pressure which immediately shuts down the pumping action. In addition the valve is normally open at the surface that will immediately start gushing fluid if there is a failure, rather than burst the surface casing water protection string. In short, the minor amounts of marginally toxic chemicals in the fracturing fluid can only be introduced to fresh water aquifers by a catastrophic failure that even so is highly unlikely and then it is immediately detectable which causes a cessation of the job limiting the volumes that could get into the fresh water. Then the pressure is immediately released where even the minor amount of contaminated water is flowed by and removed. Reports of vast contamination therefore are intrinsically false.
Hydraulic fracturing has been blamed for an increase in earthquakes. Although fracturing fluid may invade a fault deep underground and act as a lubricant causing a slippage, I find this highly unlikely to cause a major earthquake, simply due to the relatively minor volumes of fracture fluid that would only affect a very small area of any fault. One must not lose sight of the large areas required to affect a major fault slippage. Let me assure everyone that if possible we would love to affect something this large to produce more oil and gas. Unfortunately the physics and economics prohibit the ability to affect such a large area. Secondarily the USGS has recently blamed the increase of minor earthquakes(less than 3.0) on saltwater disposal wells. These wells have been in existence for 50 years also so there’s nothing new to believe they are responsible and produced water does not necessarily come from hydraulically fractured wells. If true we should have been experiencing earthquakes for the last 50 years.
The real problem I see in the shale plays is not about hydraulic fracturing it is the future of the natural gas business that the euphoria of the excess supply and the price collapse will result in a severe feast and famine with the idea of infinite sustainable supply. First of all the entire oil and gas business since its inception has always been feast or famine. Prices go up causing a frenzy of activity at the same time they are causing a reduction in consumption. Supply is increased to level that the production/consumption curves cross and the prices collapse causing a famine and cessation of drilling while at the same time lower prices cause consumption to increase. When the drilling stops it doesn’t mean that the current rate of production will be maintained, but will immediately begin dropping. For the shale gas plays to be economical requires a natural gas wellhead price of at least $6/mcf. The current prices of $2.50/mcf at the wellhead virtually assure that 80% of the current wells drilled will never payout their costs. As far as feast or famine the shale plays will be even more severe because the decline rate of a shale gas well will be as much as 90% during the first year and certainly no less than 70%. The drilling frenzy that created the excess supply and price drop has virtually shut down. The excess capacity will disappear rapidly due to the rapid decline in deliverability at the same time that the bargain energy price of natural gas versus oil will increase consumption of gas. This result will occur just about the time that the excess production capacity will rapidly disappear. Since storage is limited and drilling takes about a year to catch up with the market then there is a likelihood of severe shortages. Due to the excessive decline rates in wells that require hydraulic fracturing the normal oil field feast and famine will occur on shorter time frames.
Hydraulic fracturing is not new technology. The industry has been fracturing wells for over 50 years. The process is expensive and requires extensive design and expertise. The current surge of the practice is primarily because of higher energy prices making the practice more economical in reservoirs that at lower prices were uneconomical. The purpose of fracturing is to increase the rate of production from very low permeability reservoirs. If done properly the process entails making a “crack” in the oil saturated rocks by injecting water that has been turned into “jello” at a rate and pressure beyond the capacity of the porous formation to absorb. This crack is then filled with a “proppant” generally sand that keeps the fracture from closing, thereby creating a flow path to the wellbore. In essence, a properly designed and executed “frac” job will increase the effective diameter of the wellbore from 8 inches to as much as 20 feet. As anyone should be able to imagine you can move a lot more fluid through a pipe with a 20 foot diameter than with an 8 inch diameter.
In order to accomplish this, it is imperative that the fracture be confined to the producing formation and not allowed to go any other places where it will not help the well produce. Why would anyone want to spend a million dollars to fracture a well to increase production and not take the precautions to make sure it went where it will do the most good? In short, the arguments about hydraulic fracturing affecting fresh water horizons as a common practice are not true. Like anywhere with a concentration of horsepower there is always danger. Like the space shuttle that blew up had concentration of 1,000,000+ horsepower. Your car probably has 200 hp and ends up being dangerous and kills 40,000 people a year, but I don’t hear anyone trying to ban cars. Similarly, there are undoubtedly some failures during fracture stimulations. However, when I am personally performing a frac-job and observe a dramatic pressure change indicating the fracture is not going where I want, the job is shut down immediately. From a catastrophic failure to shut down of the job will take less than 30 seconds. Why would I want to spend that much money and not put the fracture in the right place?
The toxic chemicals myth should also be addressed. To begin most hydraulic fracture jobs are composed of 99% water. The primary ingredients we use are polymers that cause the water to form a gel. These polymers are not anymore toxic than any other gelling agent. The rest of the proprietary mixtures are not more excessively toxic than the chemicals under your sink. These mixtures are generally pumped inside at least two and as many as four high strength steel casings that are cemented concentrically in the hole. Whether we are going to fracture or not a “surface casing” string is always run and cemented to a depth to protect any freshwater aquifers from contamination during the drilling and production phase of an oil well. Since the formations that produce oil may be a mile or more underground and the fresh water aquifers seldom exists below 1000’ from the surface it is highly unlikely to be able to fracture into any freshwater outside the casing protection. It is physically impossible to make a fracture grow in height much more than 1000’ and that would be a poor fracture design. So therefore how can one expect a fracture fluid to get into fresh water except in very unusual circumstances caused by a mechanical failure through at least 2 strings of high strength steel pipe which will be easily observable by a dramatic change in surface treating pressure which immediately shuts down the pumping action. In addition the valve is normally open at the surface that will immediately start gushing fluid if there is a failure, rather than burst the surface casing water protection string. In short, the minor amounts of marginally toxic chemicals in the fracturing fluid can only be introduced to fresh water aquifers by a catastrophic failure that even so is highly unlikely and then it is immediately detectable which causes a cessation of the job limiting the volumes that could get into the fresh water. Then the pressure is immediately released where even the minor amount of contaminated water is flowed by and removed. Reports of vast contamination therefore are intrinsically false.
Hydraulic fracturing has been blamed for an increase in earthquakes. Although fracturing fluid may invade a fault deep underground and act as a lubricant causing a slippage, I find this highly unlikely to cause a major earthquake, simply due to the relatively minor volumes of fracture fluid that would only affect a very small area of any fault. One must not lose sight of the large areas required to affect a major fault slippage. Let me assure everyone that if possible we would love to affect something this large to produce more oil and gas. Unfortunately the physics and economics prohibit the ability to affect such a large area. Secondarily the USGS has recently blamed the increase of minor earthquakes(less than 3.0) on saltwater disposal wells. These wells have been in existence for 50 years also so there’s nothing new to believe they are responsible and produced water does not necessarily come from hydraulically fractured wells. If true we should have been experiencing earthquakes for the last 50 years.
The real problem I see in the shale plays is not about hydraulic fracturing it is the future of the natural gas business that the euphoria of the excess supply and the price collapse will result in a severe feast and famine with the idea of infinite sustainable supply. First of all the entire oil and gas business since its inception has always been feast or famine. Prices go up causing a frenzy of activity at the same time they are causing a reduction in consumption. Supply is increased to level that the production/consumption curves cross and the prices collapse causing a famine and cessation of drilling while at the same time lower prices cause consumption to increase. When the drilling stops it doesn’t mean that the current rate of production will be maintained, but will immediately begin dropping. For the shale gas plays to be economical requires a natural gas wellhead price of at least $6/mcf. The current prices of $2.50/mcf at the wellhead virtually assure that 80% of the current wells drilled will never payout their costs. As far as feast or famine the shale plays will be even more severe because the decline rate of a shale gas well will be as much as 90% during the first year and certainly no less than 70%. The drilling frenzy that created the excess supply and price drop has virtually shut down. The excess capacity will disappear rapidly due to the rapid decline in deliverability at the same time that the bargain energy price of natural gas versus oil will increase consumption of gas. This result will occur just about the time that the excess production capacity will rapidly disappear. Since storage is limited and drilling takes about a year to catch up with the market then there is a likelihood of severe shortages. Due to the excessive decline rates in wells that require hydraulic fracturing the normal oil field feast and famine will occur on shorter time frames.
