Shale gas production decline trend over time in the Barnett Shale

Abstract

Natural gas produced from shale formations in the United States over the past decade have altered the oil and gas industry remarkably. The Barnett shale was at the forefront of the shale gas revolution in the United States and was considered to be the highest producing natural gas field in the United States until 2012, yielding the top producer spot to the Marcellus shale. Due to the uncertainty regarding the accurate determination of Estimated Ultimate Recoverable (EUR) in shale gas reservoirs, this paper aims to assess EUR values for the Barnett shale using empirical decline curve methods like the Arp's hyperbolic, Modified Arp's hyperbolic and Doung's method. In addition, we investigated the economic viability of wells over time in the Barnett under various probabilities of success. Throughout this paper, reference is made to two key publications where a similar work was carried out for various shale plays in the United States, including the Barnett shale -though only the Arp's hyperbolic decline was employed.The dataset in this paper consisted of more horizontal wells from covering more counties within the Barnett shale compared to other similar studies. We conclude that either the Arp's hyperbolic or Doung's method can be used to forecast EUR in the Barnett shale as only marginal differences were observed. This is on the basis that production history exceeds 10 months (a maximum of 80 months production history was used). We also obtained reliable and conservative estimates of EUR compared to previous studies.

Influencing Factors and Mathematical Prediction of Shale Adsorbed Gas Content in the Upper Triassic Yanchang Formation in the Ordos Basin, China

“…The dissolved gas can also transform into free gas during exploitation, indicating that the primary productivity in the continental shale maybe low, but its stable production time may be long and thus determining the final gas production because of its larger adsorption gas ratio. The predicted trend of gas production for the Yanchang shale is similar to the gas production rate and decline trend in the Barnett Shale [77]. The initial gas production rate in the Barnette Shale is generally lower than other major shales in the US like Eagle ford, Marcellus and Haynesville [77].…”

“…The predicted trend of gas production for the Yanchang shale is similar to the gas production rate and decline trend in the Barnett Shale [77]. The initial gas production rate in the Barnette Shale is generally lower than other major shales in the US like Eagle ford, Marcellus and Haynesville [77]. Mavor [78] revealed it was due to the adsorption gas content of the Barnette Shale occupied about 60% of the total shale gas reserves.…”

Development of Shale Gas Prediction Models for Long-Term Production and Economics Based on Early Production Data in Barnett Reservoir

“…An approximation of 1.25 trillion cubic meters of gas can be technically recovered from the Barnett reservoir [19][20][21]. Compared to the other major shale gas plays in the USA, the Barnett shale has the lowest initial gas production rate and the lowest decline rate after 5 years of production [14,15]. The typical reservoir depth is 1980-2590 m, and the reservoir thickness is 30-180 m [22].…”

“…The performance of a well is related strongly to the production rate, particularly for a shale gas well whose production rate is featured by a high initial decline rate after peak production [14,15]. Therefore, early production data can be used as a key parameter for predicting the performance of a shale gas well at the end of life.…”

An Analytical Model for Capturing the Decline of Fracture Conductivity in the Tuscaloosa Marine Shale Trend from Production Data

“…The empirical production decline models were not derived based on engineering principles. They are mainly utilized for evaluating field development projects on the basis curve fitting to the production history data [16]. Besides, empirical production decline models are mostly applicable to boundary-dominated flow conditions that are often the case for conventional reservoirs.…”