Engineering sciences/ 10 Mining

Phd in technical sciences Fattakhov Irik Galikhanovich

SEI of HPE "Ufa State Petroleum Technological University" branch in Oktyabrsky city, Russia

DEVELOPMENT CONDITION DIAGNOSTICS ON THE EXAMPLE OF MAY OIL FIELD

May oil field statistical modeling [1,2] was performed for the purpose of development condition diagnostics according to 6 main trade characteristics: oil flow rate, tonne/month; liquid flow rate, m3/month; production water cutting, %; liquid flow rate in sheeted conditions, m3/month; the volume of pumped water, m3/month; ensuring selection of liquid withinjection, % [3].

Two periods of field development were considered for comparison: 2003-2006 – on a field it wasn't carried out cyclic flooding (in 2005 there was one trial delivery well) and 2007-2011 – cyclic flooding was carried out according to the following scheme: from May to September all delivery wells were disconnected, and from October to April all functioned. For both cases fluctuation coefficients φ [4,5], works of system of development showing stability on the example of flooding were calculated. When studying a field it is received for each of two periods on 16 comparative charts with rated data. Each diagram shows certain groups of considered parameters. Because of limitation of work volume from all selection consisting of 32 charts, we will bring only four, representing the greatest interest from the point of view of their interpretation.

The received φ values in all respects for the Mayskiy field during the first and second periods are shown in table 1. As appears from [4,5] the lesser fluctuation, the more process is stable. The greatest interest from regulation point of view represents water cutting of extracted B production and Qinj volume of injected water. After introduction of non-stationary flooding watter cutting coefficient φ increased a little and water injection coefficient decreased. Respectively this action positively affected water cutting as a whole, in consequence of layer work in two modes: capillary impregnation and filtration on channels. In turn the coefficient φ went down for injection, because of duration and an inequality of two half-cycles in a year. The explanation of that is covered in risk of freezing of delivery wells mouth during the winter period, because of constantly low temperatures around a field. Therefore regulation of non-stationary flooding with use of measures for the mouth freezing prevention of delivery wells [6,7] for elimination of interruptions in its work that will cause increase φ and according to stability of work is necessary.

Table 1 – Values of coefficient of fluctuation φ for the May field during the first and second periods

 

Qo

Ql

B

Qll

Qinj

Qinj/Qll

First period

4,36

3,85

1,81

3,93

3,35

6,26

Second period

3,41

6,06

2,85

6,20

1,16

11,69

Let's consider figures 1 and 2 where in both cases to winter decrease in pumping Qinj water there corresponds also reduction of oil production of Qoil that is peculiar to all to years of development. This regularity has directly proportional character. Schedules of figures 3 and 4 show that the increase in water cutting of B is at the bottom of reduction of amount of extracted Qí oil, i.e. dependence is inversely proportional. For this reason planning [8] and carrying out water insulating works [9] in extracting wells with the greatest fluctuations of parameter of water cutting is necessary.

Figure 1 – Schedules of rated indicators on oil production of Qoil and volume of pumped Qinj  water during the first period (abscissa axis corresponds to monthly changes)

Figure 2 – Schedules of rated indicators on oil production of Qoil and volume of pumped Qinj water during the second period

Figure 3 – Schedules of rated indicators on water cutting of extracted production of B and volume of pumped Qinj water during the first period

 

It is necessary to emphasize importance of increase of coefficient of fluctuation on the example of table 2 with data of the missed oil production in a year during the first and second periods. Losses of oil were counted on the basis of data during stable work of non-stationary downloading. Let's note that the annual missed production is considered only for other period of year (not entering into the period of stable work).

 

Figure 4 – Schedules of rated indicators on water cutting of got production of  B and volume of pumped Qinj water during the second period.

 

From the above-stated data follows that during the first period because of instability of process of flooding the enterprise lost about 5 thousand tons of oil every year and about 20 thousand tons for the considered period. During the second period of loss decreased to 1,25 thousand tons a year and for the reporting period made about 6,5 thousand tons of oil. This calculations were carried out against decrease in average outputs of the second period for 5% in comparison with the first.

 

Table 2 – The missed oil production in a year

Period

Theaverage daily lost flow rate

The percentage from average daily production

Annual loss of production

Δql, t/d

qpl, %

Ql, t

First

20,28

11,05

4928,18

Second

5,18

3,63

1257,84

 

As the recommendation we will tell about need of increase of coefficient of fluctuation on parameters of volume of pumped Qinj water and water cutting of got production of B to 10. What as it was spoken earlier, requires introduction of effective measures for the prevention of freezing of the mouth of delivery wells. And also application of techniques of forecasting of nature of flood and determination of expediency of carrying out water insulating works [8] with application of new blocking structures [9].

 

List of reference:

1.                 Mirzadzhanzade A.H., Stepanova G.S. Matematicheskaja teorija jeksperimenta v dobyche nefti i gaza. M., «Nedra», 1977, 229s.

2.                 Kul'bak S. Teorija informativnosti i statistiki. M., «Nauka», 1967, 408s.

3.                 Promyslovye dannye OAO «NK«Rosneft'» po Majskomu mestorozhdeniju za 2003-2011 gg.

4.                 I.G. Fattakhov, R.R. Kadyrov, L.S. Kuleshova. The investigation of non-stationary waterflood using statistical approaches// European Science and Technology: materials of the international research and practice conference, Vol. I. Bildungszentrum Rdk e.V. Wiesbaden, Germany, 2012. p.182-186.

5.                 I.G. Fattakhov. The consideration of the cyclic injection through the example of Stakhanovskiy oil field// International scientific periodical «Modern fundamental and applied researches». 2012.- ¹4(7). p. 70-73.

6.                 Kadyrov R.R., Fattahov I.G., Kuleshova L.S. Primenenie jelektroprogreva dlja preduprezhdenija zamerzanija ust'ja nagnetatel'nyh skvazhin / //Neftepromyslovoe delo. - 2012. - ¹4. - S. 32-35.

7.                 Fattakhov I.G. The method of wellhead thermal insulation in injection wells / I.G. Fattakhov, R.R. Kadyrov, L.S. Kuleshova. //Electronic scientific journal "Oil and Gas Business", 2012, Issue 1, pp. 117-120.

8.                 Fattahov I.G. Prognozirovanie haraktera obvodnenija i celesoobraznosti provedenija vodoizoljacionnyh rabot / R.R. Kadyrov, I.G. Fattahov, Je.R. Hamidullina, A.V. Patlaj// Inzhener-neftjanik. - 2012. - ¹ 3. - S. 55-60.

9.                 Fattahov I.G., Kadyrov R.R. Rezul'taty primenenija tehnologii na osnove vodnyh rastvorov aljumohlorida pri provedenii vodoizoljacionnyh rabot //Neftepromyslovoe delo. - 2010. - ¹1. - S. 44-46.