Message-ID: <507467726.148.1579994040798.JavaMail.zibwiki@www03.zib.de> Subject: Exported From Confluence MIME-Version: 1.0 Content-Type: multipart/related; boundary="----=_Part_147_1591728816.1579994040796" ------=_Part_147_1591728816.1579994040796 Content-Type: text/html; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Content-Location: file:///C:/exported.html Optimization of the gas-lift process

# Optimization of the gas-lift process

The = gaslift method is of special importance at the initial period after the flo= wing of the oil fields [1,2, 3]. The motion in the gaslift process is known= to obey the hyperbolic nonlinear partial differential equations. Therefore= , at gaslift operation of the borehole cavity the problem of optimization w= ith boundary control is of special interest. However, with the original for= mulation of the problem of optimal control one encounters certain difficult= ies. The averagings of the hyperbolic equation describing the time profile = of motion by the gaslift method are given here [1, 3]. It rearranges a part= ial derivative equation in the nonlinear ordinary differential equations. T= he strategy of constructing the objective quadratic functional with the use= of the weight coefficients lies in minimizing the volume of the gas inject= ed in the annular space and maximizing the desired volume of the gas-liquid= mixture (GLM) at the end of the lifter. In this case, the aim lies in solv= ing the corresponding optimization problem where the volume of the injected= gas which is used as the initial data and plays the role of the control ac= tion.
The impossibility of using the standard methods to construct the = corresponding controllers is a disadvantage of this approach. Yet, since at= certain time intervals the boundary control is constant, the numerical dat= a obtained can be readily compared with the production data.
Using the = method of time averaging, the partial derivative equations of motion of gas= and GLM motion proposed in  are rearranged in the ordinary differential= equations. The problem of optimal boundary control with the quadratic func= tional is formulated on the basis of the above considerations. The results = obtained can be used to control the gaslift borehole cavity at oil extracti= on. For solution of the considered problem of boundary controls, the gradie= nt method  is modified by describing the corresponding Euler=E2=80=93Lag= range equations .

References

1. F. A. Aliev, M. K. Ilyiasov, M. A. Dzhamelbekov, M= odelling of operation of the gaslift borehole cavity. Dokl. NANA, 2008, 4, = 107-116.

2. F. A. Aliev, N. A. Ismailov, N. S. Mukhtarova, Alg= orithm to determine the optimal solution of a boundary control problem. Aut= omation and Remote Control, 2015, 4, 627-633.

3. A. H. Mirzadzhanzade, I. M. Ametov, A. M.Khasaev, = Technology and Machinery of Oil Extraction. Moscow, Nauka, 1986.

4. A. Bryson, Yu Chi Ho, Applied Optimal Control, Wal= tham, Blaisdell, 1969.

Contributor:

Prof. Jaan Lellep, U= niversity of Tartu

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