Time-tracking tests and interpretation for a horizontal well at different wellbore positions

Abstract

We have developed a time-tracking test method for pressure buildup tests of horizontal wells to reduce the costs associated with testing wells. The time-tracking test method requires several tests that are performed chronologically from the midsection of the horizontal wellbore to the kickoff point. The purpose of time-tracking tests is to determine the production conditions of horizontal wells that allow the tests to be conducted at the kickoff point. Two horizontal wells associated within a sandstone oil reservoir were specifically chosen to determine how our time-tracking test method is to be implemented. The two wells had completely different production conditions. One had a small gas rate and a large water cut, whereas the other had a large gas rate and a small water cut. We recorded and analyzed the tested pressure data at numerous wellbore positions along the same horizontal well. Then, we interpreted the tested pressure data and compared the test results at different points along each well using the test curve shape and the interpretation parameter values. Through comparisons of the two wells, we found that the well-test curve shape and the interpretation results of tests performed above the kickoff point were completely different from those of the tests at the midsection of the horizontal wellbore under the conditions of a large gas rate and a small water cut. If a horizontal well has a small gas rate and a large water cut, the well can be tested at the kickoff point in the well using the wireline. We recommend that field petroleum engineers adopt the time-tracking test method to judge whether their horizontal wells should be tested at the kickoff point.

Evaluation of Liquid Production and Water Injection Profiles of Horizontal Well by Pressure-Transient Analysis: Field Cases

“…Cheng et al 21 developed a well-test model for the horizontal wells with nonuniform production rate considering the segmented oil production and various skin factors in different production segments by Green's function and Newman's product tool. Nie et al 22,23 established a semianalytical model for horizontal wells in a homogeneous, dual, and triple-porosity reservoir and then developed a time-tracking test method to reduce the well testing costs. Sureshjani et al 24 proposed the procedures to estimate the formation permeability distribution by pressure transient analysis.…”