Increase the speed of drilling with the use of an ejector pump
It is well known that the mechanical drilling speed is one of the main factors affecting technical and economic indices of drilling. We analyzed the main trends of development of science and technology in this field and has created a unique device that allows to increase the mechanical drilling speed, but also the excavation bit. This device is Nadolny ejector pump EGG that can be used during rotary drilling when drilling with a PDM, even when drilling with turbodrills.
EXPERIENCE OF APPLICATION MADDALUNO EJECTOR PUMP FOR INCREASING TEP DRILLING..jpg)
Experience the transaction of oil and gas wells shows that with the increase of drilling depth in dramatically reduced performance of the bits. The main reason for this, according to most domestic and foreign researchers, is the change in downhole conditions of rock failure. This refers to the influence of such factors as the presence of pore pressure, pore, differential and total hydrostatic and hydrodynamic pressures, and mechanical properties of rocks.
In this regard, was performed numerous laboratory and field studies of the impact of these factors on the conditions of fracture of rocks, in which it was established:
1. Differential pressure is one of the main factors determining the MATIC performance of the drill bit;
2. Intensive decrease in the mechanical rate of penetration occurs at the initial time of the growth differential pressure up to 3.5 MPa. A further increase in differential pressure (P) is accompanied by the stabilization of the mechanical rate of penetration (Vм);
3. With a reduction in differential pressure Vм increases;
4. With the increase in the load on the bit increases the sensitivity Vм to changes in differential pressure;
5. It is impossible to establish a General dependence Vм = f (R) according experienced drilling. (1)
Thus, it is currently believed that under the existing regime-Mach drilling differential pressure, as a rule, is the main factor determining the TEP drilling. With increasing R to 1.4...7.0 MPa, based on the conditions of drilling mechanical rate of penetration may decrease to be sewn in 2...5 times.
These questions are important not only for drilling but also for qualitative opening of the productive formation, its rapid development and involvement in development.
In modern terminology, a differential pressure determines the static force holding the sludge on the bottom, and is numerically equal to the difference between hydrostatic pressure and pore (pore). But the mud there is a hydrodynamic pressure, which also provides negative pressure in the bottom hole. Consequently, downhole when circulation of drilling mud acts a depressing pressure which is the sum of hydrodynamic pressure and differential equations.
The most common methods of reducing the differential pressure is drilling on the balance and aeration of drilling mud.
In addition to the traditional methods minimize hydrodynamic losses, there are other methods based on the use of some physical effects:
the use of the Toms effect, which is that in adding to the water some polymers achieved a significant 30% reduction in the pressure losses in turbulent flow regime. By lowering the friction of the precursor States include CMC, polyacrylamide, polyisobutylene and a number of other Prime ditch. There is an optimal mass fraction of polymer at which the maximum effect. It depends on the nature of the polymer, the diameter of the pipeline water, the density of the fluid, and the criterion Re.
use the effect of "early turbulence" - some additives to drilling mud to reduce the generalized parameter Reynolds Reкр, change the flow regime, causing the "early" turbulence. This dramatically improves the external and, most importantly, cleaning ability of the drilling fluids. Found that the oil and CMC-500 are active stimulators of the earlier turbulent activity, and the activity of CMC-500 is much higher than oil. So when the content of CMC-500 in drilling mud 0,35%, Reкр decreased in 14 times in comparison with the national Institute of justice Reкр initial solution.
EXPERIENCE OF APPLICATION MADDALUNO EJECTOR PUMP OF EGG
To reduce the differential pressure, we have developed a device that uses the principle of ejection - Nadolny ejector pump EGG. This design has small gabaritizmeri and can be used in the different BHA as during rotary drilling and drilling downhole motors.
To use EGG methodology was developed for optimization of hydraulic program of washing of wells, including the choice of rheological parameters of drilling fluid, the diameter of the cylinder liners and the performance of drilling pumps, as well as calculating the number and diameters of nozzles in the bit.
EGG works in the following way:
1. Select desired hydraulic regime and on bit installed nozzles are designed size. Going the standard BHA – EGG fits over the chisel.
2. BHA down to the slaughter, in the working area of the bit and EGG served the drilling mud.
3. Part of the drilling mud supplied to the bit - part on AGG. (direction arrows)
4. In sloping channel, the liquid acquires a high speed and creates vacuum at the junction of the inclined and vertical channels. Due to this, fluid from the working area of the bit, together with the sludge through a vertical channel with high velocity flows in inclined, there is mixed with working fluid and with high speed comes out of the sloping channel. Further, the jet of solution hitting the wall of the well, almaterra it, is changing the direction of movement. Simultaneously, the rotation of the bit with ASH, formed a hydraulic funnel, creating an additional effect of ejection between the borehole wall and the housing AGG.
Test EGG in the fields of Sakhalin, Saratov, Tatarstan, Western Siberia. Drilled over 100 wells with different drilling methods, criteria efficient to use this technology. The results of the work showed that the increase of drilling speed and penetration on the bit depends on the differential pressure of AIG, the minimum differential pressure shall be not less than 3.0 MPa. The increase in drilling speed is 20...25%, and the penetration of the bit – 30...35%. With further increase in differential pressure increase of the indicators also increased: when the differential pressure of EGG 6.0 MPa, the increase in speed is 80...100%, penetration – 90...120%.
The average performance of EGG in Russia
When rotary drilling it has been observed that when the differential pressure on the bit and EGG 4.5 to 5.0 MPa drilling performance on mechanical-cal speed and sinking outperformed drilling obtained in these ranges when using PDM, but without EGG 30%. Also has been widely tested EGG when drilling with hydraulic downhole motors in the fields of the Montenegrin and Erxofoe of OAO “Nizhnevartovskneftegaz”. In General AGG were tested at 30 wells in the range of 50 - 1000 m and 2200 - 2800M. When drilling a conductor (interval 50 - 1000m) has been used drill bit 295,3 MZ-GNU and SSGW. When comparing not-making has resulted in the birth intervals of a set of Zenith angle. The average value of the mechanical soon-STI in the baseline wells is 23.9 m/h. the Average value of the mechanical speed for the wells drilled with the use of EGG, is 41.9 km/h. The most significant results when drilling vertical sections, for example, with basic drilling well No. 50916, the interval 58 - 754м was drilled for 27 hours, and the use of EGG, well No. 41040, inter-shaft 42 - 1013м was drilled in 24 hours.
When drilling under the production casing, for comparison took into account only the interval 2200 - 2800M. As a base comparison, it was taken bliznaja-ing wells with the same departure and azimuth ± 300. The average value of the fur-cal speed through the base wells made up 8.56 m/h, penetration rate is 46.6 m. the Average value of the mechanical speed for the wells drilled with the use of EGG, was 11.4 m/h, the penetration - Increase to 71.4 m, compared to the baseline drilling, mechanical drilling rate was 33%, and the penetration - 53%. On average, the savings of bits in the range of 2200 - 2800M is 2pcs. at each well.
When drilling with a turbodrill using EGG indicators somewhat lower, since the turbodrill take the basic hydraulic power pumps and the pressure drop across the bit and EGG was not more than 3,0...4,0 MPa.
Comparison of drilling results in the application of ASG in Libya
well L81 (using EGG) and well L79 (without the use of EGG)
Cavernomas before and after work EGG in the well
Drilling without the use of EGG(top) and with the use of EGG (bottom).
The work was carried out on two wells on a single Bush.
Based on the foregoing, we can draw the following conclusions:
Sustainable mode of EGG (i.e. increased rates of drilling by 25...30%) occurs when the differential pressure on it from 3.0 MPa, with a further increase in differential pressure increase the mechanical drilling speed increases almost linearly.
The penetration of the bit also increases in proportion to the pressure drop over EGG, but the rate of increase of this indicator is slightly higher than the rate of increase in the mechanical drilling speed, due to the exclusion of the phenomenon of recirculation of slurry in the vicinity of the drill bit. Due to this, dramatically reduces the rate of wear-out of drill bits.
The use of EGG prevents "balling" on the bit and by remark allows drillers to reach the bottom without landing and study.
When conducting cavernosometry it was observed that in the intervals drilled with the use of EGG, the diameter of the borehole was close to the nominal.