彩票走势图

In the low permeability (permeability 10md) and ultra-low permeability (permeability 1md) oil and gas reservoir, the oil supply capacity of the reservoir is very poor and cannot be continuously exploited. The development of such an oil layer generally adopts the intermittent oil production, and the intermittent oil production makes the well testing interpretation problem very complicated: the formation continuously produce oil during the production stage or the stop production stage; and during the production, the liquid level in the wellbore is also rising, and the pressure drop funnel of the formation is also changed; Both the production and the bottom hole pressure are unknown.

By Chengong science and technology, the mathematical model of intermittent oil production is set up according to the characteristics of the intermitted pumping and lifting oil  production, and a well testing analysis method for full-pressure historical simulation is put forward.

For the development well, because of the long production time,  the original state can not be obtained, so the first stage of the test should be pressure recovery. Through the pressure recovery of the first stage, the pressure drop funnel before the first stage shut-in can be inverse-derived approximately, and the pressure history can be calculated according to this pressure drop funnel.

In the calculation of the pressure history of the lifting well, because the lifting time is very small compared with the recovery time, the lifting time is ignored in the wellbore pressure calculation, and it is considered that the pressure changes instantly, that is, the pressure changes during the lifting period are step changes, and the pressure changes during the shutdown period can be considered as DST flow, it can calculate the recovery automatically (of course, the user can also input). For inter-pumping oil exploitation, because the amount of formation flowing into the wellbore is not equal to the amount that extracted from the wellbore, it is necessary to input the flowrate when the flow reaches stable, meanwhile, the stable flow time should be confirmed.

The application of intermit well testing in Daqing Oil Field is utilized. Not only the result of interpretation is obtained, but also the working system of intermitted pumping and lifting oil production is optimized according to the interpretation results.