Table of Contents
What is Horner plot?
A type of build up pressure test plot. The Horner plot uses a recording of the pressure during pressure build-up to predict its virgin reservoir pressure. The slope (m) of the extrapolated line reflects the nature of the reservoir rock and the fluids flowing through the rock.
What is a inflow test?
Summary. Negative tests, or inflow tests, are conducted to verify the integrity of well barriers in the direction of potential flow, subjecting a barrier to a negative pressure differential, while monitoring for signs of a leak. A common practice is to observe the rate of flowback from the well.
What is a negative pressure test on an oil well?
A test in which the hydrostatic pressure is reduced such that the net differential pressure direction is from the formation into the wellbore.
What is pressure build up?
1. n. [Well Testing] A rise in well pressure as a function of time observed after a well is shut in or after the production rate is reduced. Buildup pressures are normally measured at or near the bottom of the hole. Antonyms: pressure drawdown.
What is bladder effect in drilling?
of the technicians suggested that the 1,400 psi pressure on the drill pipe was being. caused by a phenomenon called the “bladder effect”— heavy mud in the riser was. exerting pressure on the annular preventer, which in turn transmitted pressure to the drill pipe.
What is a formation integrity test?
A Formation Integrity Test (FIT) is a test of the strength and integrity of a new formation and it is the first step after drilling a casing shoe track. An accurate evaluation of a casing cement job and of the formation is extremely important during the drilling of a well and for subsequent work.
What is mud in Deepwater Horizon?
Deepwater Horizon’s crew needed to cement the bottom of the well, put a cap on it, and sail away. First there were many abandonment procedures, including a “negative test,” in which heavy drilling fluid (“mud”) was pulled out of the well to see whether the cement job would hold.
What is falloff test in well testing?
1. n. [Well Testing] The measurement and analysis of pressure data taken after an injection well is shut in. These data are often the easiest transient well-test data to obtain.
What is drawdown in well testing?
The drawdown test, or pressure drawdown test, refers to the process during which the changes of flowing pressure are observed when new wells or wells that maintain stable formation pressure after a long period of being shut-in produce at a constant rate.
What is drawdown pressure?
Pressure drawdown is the difference between the reservoir pressure and the flowing wellbore pressure, which drives fluids from the reservoir into the wellbore. The difference between reservoir and flowing wellbore pressure is called pressure drawdown, and this has the greatest impact on the production rate of a well.
What is the BOP Deepwater Horizon?
The blowout preventer (BOP) that was intended to shut off the flow of high-pressure oil and gas from the Macondo well in the Gulf of Mexico during the disaster on the Deepwater Horizon drilling rig on April 20, 2010, failed to seal the well because drill pipe buckled for reasons the offshore drilling industry remains …
What is a negative pressure test drilling?
A negative pressure test is considered the last critical step before a drill rig places a final cement plug, pulls up its blowout preventer, and moves on. For that test, the drill crew first had to remove the downward pressure of heavy mud being exerted by the rig on the well.
What is well integrity test?
Integrity testing involves adding a slug of clean water to a well and measuring how fast the water comes up then falls to its initial level in the well. The results of the test indicate if a well is open to the aquifer or if the well is plugged, collapsed, or otherwise not functioning properly.
What is the difference between leak off test and formation integrity test?
The main difference between Leak Off Test and Formation Integrity Test is that LOT is that the formation is pressurized till getting to the injection level.
What is injectivity test?
1. n. [Production Testing] A procedure conducted to establish the rate and pressure at which fluids can be pumped into the treatment target without fracturing the formation.
What is isochronal well test?
The isochronal test is a series of single-point tests developed to estimate stabilized deliverability characteristics without actually flowing the well for the time required to achieve stabilized conditions at each different rate.
What is a Horner plot and how is it used?
During a test, displacement occurs through the use of a lower density completion fluid — thus lowering pressure — and the well barrier is monitored for leaks. For a long time, Horner analysis has served as the industry standard for the study of negative test results, with the Horner plot being the de facto choice for recording such results.
Is the Horner plot the best way to analyze pressure transient analysis?
Tarek Ahmed, D. Nathan Meehan, in Advanced Reservoir Management and Engineering (Second Edition), 2012 The Horner plot has been the most widely accepted means for analyzing pressure buildup data since its introduction in 1951. Another widely used aid in pressure transient analysis is the plot of change in pressure Δp vs. time on a log–log scale.
How do you calculate Horner time in a well?
Plot Horner time tH = ( tF + Δ t )/Δ t as a function of shut-in time in the range 1 hr ≤ Δ t ≤ 300 hours for flowing times of 10, 100, and 1,000 hours. Is Horner time largest at small shut-in time or large shut-in time? 8-2. Use Eq. (8.2.2) to calculate dimensionless time for a well that has produced 10,000 STB/D of dry oil for 15 days.
Which Horner plot represents the fissure behavior?
Fig. 4.14 is a Horner plot of the three build-up examples of Fig. 4.12. With example A1, only one semi-log straight line is obtained during shut-in. It represents the fissure behavior.