1、5.2 Pressure Transient Analysis-Slightly Compressible Liquids1. The basis of pressure transient analysisSlightly compressible liquid 2162.6 l g( ) 3.23 0.86 9w f itwqB k tp p sk h C r The basis of well-test analysis techniques forhomogeneous-acting reservoirs is the line-source(Ei-function) solution
2、 to the diffusivity equation.0t0tqpwf2. Analysis of Constant-Rate Flow Tests0t0tqpwf2162.6 l g( ) 3.23 0.86 9w f itwqB k tp p sk h C r y = mx + b2162.6 l gt l g( ) 3.23 0.86 9w f itwqB kp p sk h C r Production at a constant rate can be considereda pressure-drawndown or flow test2162.6 l gt l g( ) 3.
3、23 0.86 9w f itwqB kp p sk h C r ,1 6 2 .6l g ,wfqBy p x t mkh y = mx + b21 6 2 . 6 l g 3 . 2 3 0 . 8 6 9itwq B kb p sk h c r 1 6 2 .6hkqBm21 . 1 5 1 l g 3 . 2 3i w ftwpp ktm c rs For the flow test121 . 1 5 1 l g 3 . 2 3i h rtwpp ksm c r For convenience, we set the flow time, t, equal to 1 hour, and
4、 usethe symbol p1hr, t=1 hr,7001,2000.1 1 10 100 1,000Elapsed Test Time, hrsPressure, psiFlow Test Graph(t2, pwf2)(t1, pwf1)Powers of 10p1hr is p at 1 hr on best-fit linePlot pressure vs. timem= p10 hr-p1 hr1 6 2 .6hkqBm1 21 . 1 5 1 l g 3 . 2 3i h rtwpp ks m c r Problems with flow Tests It is diffic
5、ult to produce a well at a strictly constant rate Even small variations in rate distort the pressureresponseAlternative to flow Tests There is one rate that is easy to maintain a flow rate of zero. A buildup test is conducted by shutting in a producing welland measuring the resulting pressure respon
6、se.3. Analysis of pressure-buildup tests00ttQPw00ttQPwq-qT T+tT T+tT T+tT T+tSuperposition method00ttQPwQ-QTTT+tT+t1 2()162 .6 l g( ) 3.23 0.869ptwk t tqBpsk h C r 2 2162 .6( ) l g( ) 3.23 0.86 9twq B k tk h C r 1 6 2 . 6 lg pw s ittqBppk h t Using Superposition method12i w sp p p p wsyp ibp1 6 2 .
7、6 qBmkh l og ( )pttx tVS. y = mx + b1 6 2 . 6 lg pw s ittqBppk h t 1 t ttbp piFor the buildup test1 6 2 .6hkqBms1 6 2 . 6 lg pw s ittqBppk h t 2162.6 l g( ) 3.23 0.86 9pw f itwktqBp p sk h C r 21 . 1 5 1 l g 3 . 2 3 l g ( )w s w f pt w pp p t tks tm c r t 121 . 1 5 1 l g 3 . 2 3h r w ftwpp ksm c r 1t 1 1pptt wfpis BHFP at the instant of shut in.5.2 Pressure Transient Analysis-Slightly Compressible Liquids（ End)
