Downhole Gauges Save Rig Time in Extended Well Tests and Provide Unique Long Term Pressure Data

2009 ◽  
Author(s):  
A Cross ◽  
Roy Quaden
Keyword(s):  
Pressure Data ◽  
Well Tests

A Data Analytics Framework for Analyzing the Effect of Frac Hits on Parent Well Production

2021 ◽  
Author(s):  
Yifei Guo ◽  
Pradeepkumar Ashok ◽  
Eric van Oort ◽  
Ross Patterson ◽  
Dandan Zheng ◽  
...  
Keyword(s):  
Horizontal Wells ◽  
Detection Algorithm ◽  
Clear Understanding ◽  
Pressure Data ◽  
Daily Production ◽  
Well Production ◽  
Different Types ◽  
Shale Formation ◽  
Well Completions

Abstract Well interference, which is commonly referred to as frac hits, has become a significant factor affecting production in fractured horizontal shale wells with the increase in infill drilling in recent years. Today, there is still no clear understanding on how frac hits affect production. This paper aims to develop a process to automatically identify the different types of frac hits and to determine the effect of stage-to-well distance and frac hit intensity on long-term parent well production. First, child well completions data and parent well pressure data are processed by a frac hit detection algorithm to automatically identify different frac hit intensities and duration within each stage. This algorithm classifies frac hits based on the magnitude of the differential pressure spikes. The frac stage to parent well distance is also calculated. Then, we compare the daily production trend before and after the frac hits to determine the severity of its influence on production. Finally, any evident correlations between the stage-to-well distance, frac hit intensity and production change are identified and investigated. This work utilizes 3 datasets covering 22 horizontal wells in the Bakken Formation and 37 horizontal wells in the Eagle Ford Shale Formation. These sets included well trajectories, child well completions data, parent well pressure data and parent well production data. The frac hit detection algorithm developed can accurately detect frac hits in the available dataset with minimal false alerts. The data analysis results show that frac hit severity (production response) and intensity (pressure response) are not only affected by the distance between parent and child wells, but also affected by the directionality of the wells. Parent wells tend to experience more frac hits from the child frac stages with smaller direction angles and shorter stage-to-parent distances. Formation stress change with time is another factor that affects frac hit intensity. Depleted wells are more susceptible to frac hits even if they are further from the child wells. Also, we observe frac hits in parent wells due to a stimulation of a child well in a different shale formation. This paper presents a novel automated frac hit detection algorithm to quickly identify different types of frac hits. This paper also presents a novel way of carrying out production analysis to determine whether frac hits in a well have positive or negative influence long-term production. Additionally, the paper introduces the concept of the stage-to-well distance as a more accurate metric for analyzing the influence of frac hits on production.

scholarly journals Signal Stations: Newly Digitized Historical Climate Data of the German Bight and the Southern Baltic Sea Coast

2016 ◽  
Vol 33 (12) ◽  
pp. 2735-2741 ◽  
Author(s):  
Dörte Wagner ◽  
Birger Tinz ◽  
Hans von Storch
Keyword(s):  
Baltic Sea ◽  
Spatial Data ◽  
German Bight ◽  
Observation Data ◽  
Climate Data ◽  
Pressure Data ◽  
Southern Baltic Sea ◽  
Southern Baltic ◽  
Sea Coast

AbstractAt the German Meteorological Service in Hamburg, handwritten journals of meteorological observation data of 164 signal stations exist that were digitized. These data contain long-term time series of up to 125 years for the period 1877–1999 and allow for studies of regional meteorological conditions with greatly improved spatial resolution. Wind and air pressure data of selected signal stations along the German Bight and the southern Baltic Sea coast show a spatial data homogeneity that allows for an improved description of two historical storms, in 1906 and 1913. This is the first presentation of signal station data.

scholarly journals Glacial variations on a meso-scale: examples from glaciers in the Aurland Mountains, southern Norway

1997 ◽  
Vol 24 ◽  
pp. 130-134
Author(s):  
Arve M. Tvede ◽  
Tron Laumann
Keyword(s):  
Dynamic Condition ◽  
Snow Accumulation ◽  
Pressure Data ◽  
Volume Changes ◽  
Mountain Area ◽  
Area Distribution ◽  
Westerly Winds ◽  
Southern Norway ◽  
Long Term Studies

Mass-balance measurements carried out since 1963 on six glaciers in southern Norway indicate that glaciers to the west of the main water divide have increased their mass, whereas glaciers further east have decreased. However, when small glaciers within the same mountain area are studied, the picture is more complicated. Different exposures, the terrain forms on the upwind side and area distribution of the glaciers are important factors with regard to the effect of the wind-driven snow.The three glaciers studied in this paper are located within a 10 km radius in the Aurland Mountains, but differ in size, exposure and dynamic condition. Volume changes were calculated from two repeated mappings of two glaciers. Svartavassbreen increased in volume in all areas; Storskavlen decreased over most of its area and increased in some parts. Vargebreen has lost nearly all its ice mass in the eastern part, but has changed little in the western part. It is concluded that the volume changes found on these glaciers mainly reflect changes in local snow accumulation. Analysis of air-pressure data from the period 1952–94 is presented and supports the hypothesis that there has been a change to stronger westerly winds from the mid-1960s onwards.It is recommended that glaciers chosen for long-term studies of volume changes should represent different exposures. The topography of the surrounding terrain is also important.

scholarly journals Glacial variations on a meso-scale: examples from glaciers in the Aurland Mountains, southern Norway

1997 ◽  
Vol 24 ◽  
pp. 130-134 ◽  
Author(s):  
Arve M. Tvede ◽  
Tron Laumann
Keyword(s):  
Dynamic Condition ◽  
Snow Accumulation ◽  
Pressure Data ◽  
Volume Changes ◽  
Mountain Area ◽  
Area Distribution ◽  
Westerly Winds ◽  
Southern Norway ◽  
Long Term Studies

Mass-balance measurements carried out since 1963 on six glaciers in southern Norway indicate that glaciers to the west of the main water divide have increased their mass, whereas glaciers further east have decreased. However, when small glaciers within the same mountain area are studied, the picture is more complicated. Different exposures, the terrain forms on the upwind side and area distribution of the glaciers are important factors with regard to the effect of the wind-driven snow. The three glaciers studied in this paper are located within a 10 km radius in the Aurland Mountains, but differ in size, exposure and dynamic condition. Volume changes were calculated from two repeated mappings of two glaciers. Svartavassbreen increased in volume in all areas; Storskavlen decreased over most of its area and increased in some parts. Vargebreen has lost nearly all its ice mass in the eastern part, but has changed little in the western part. It is concluded that the volume changes found on these glaciers mainly reflect changes in local snow accumulation. Analysis of air-pressure data from the period 1952–94 is presented and supports the hypothesis that there has been a change to stronger westerly winds from the mid-1960s onwards. It is recommended that glaciers chosen for long-term studies of volume changes should represent different exposures. The topography of the surrounding terrain is also important.

Assessment of long-term antihypertensive treatment by clinic and ambulatory blood pressure: data from the European Lacidipine Study on Atherosclerosis

2007 ◽  
Vol 25 (5) ◽  
pp. 1087-1094 ◽  
Author(s):  
Giuseppe Mancia ◽  
Gianfranco Parati ◽  
Grzegorz Bilo ◽  
Alberto Maronati ◽  
Stefano Omboni ◽  
...  
Keyword(s):  
Blood Pressure ◽  
Ambulatory Blood Pressure ◽  
Antihypertensive Treatment ◽  
Pressure Data ◽  
Blood Pressure Data
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